'Occupational dermatoses from Personal Protective Equipment during the COVID-19 pandemic in the tropics - A Review'

The COVID-19 pandemic has enveloped the world and there has been a high incidence of occupational dermatoses related to Personal Protective Equipment (PPE) amongst healthcare workers (HCWs) during this period. Prevention and management of these conditions will not only improve staff morale and quality of life, but will also minimize the risk of breaching PPE protocol due to such symptoms. The tropical climate in Singapore predisposes HCWs to more skin damage and pruritus due to intense heat, high humidity and sun exposure. The effects of friction, occlusion, hyperhidrosis and overheating on the skin in the tropics should not be neglected. Preventive measures can be taken based on our recommendations, and the working environment can be made more conducive for frontline HCWs. We review the literature and discuss various preventive and management strategies for these occupational skin diseases for our frontline HCWs, especially those working in less controlled working environments beyond the hospital in Singapore. Shorter shifts and frequent breaks from PPE are recommended. Duration of continuous PPE-usage should not exceed 6 h, with breaks in non-contaminated areas every 2-3 h to hydrate and mitigate the risk of skin reactions. Other strategies, such as teledermatology, should be considered so that consultations can remain accessible, while ensuring the safety and well-being of our clinical staff.

Epidemiology of post-adolescence acne and adolescence acne in Singapore: a 10-year retrospective and comparative study

INTRODUCTION

Acne vulgaris commonly affects adolescents. But recent reports suggest a rising prevalence of post-adolescence acne. While there are few reports on post-adolescence acne, there are even fewer reports comparing adolescence acne and post-adolescence.

METHODS

Epidemiological data of adolescence (<25 years) and post-adolescence (≥25 years) acne patients diagnosed between 2004 and 2013 in a tertiary dermatology referral centre was analysed. From the pool of patients seen in 2010, 80 adolescence and 84 post-adolescence acne patients' epidemiological characteristics and treatment responses were analysed.

RESULTS

During the 10-year study period, there was an increase in the number and proportion of acne cases. In 2004, 4447 (5.77%) of all new diagnoses made were of acne vulgaris. The proportion rose to 5723 (8.13%) in 2013. There were consistently more female than male acne patients. The proportion of post-adolescent cases remained constant at about 30% of all acne patients seen. Mean age of acne vulgaris patients decreased from 23.1 years in 2004 to 22.6 years in 2013. In the subgroup analysis, there were more males than females with adolescence acne (61.3% vs. 38.8%, P < 0.01) and more females with post-adolescence acne (69.0% vs. 31.0%, P < 0.01). Thirty-four (40.5%) post-adolescence acne patients had acne from adolescence persisting into adulthood. Comedonal acne was more prevalent in the adolescence acne patients (58.8% vs. 40.5%, P = 0.019), whereas cystic acne was more prevalent in post-adolescence patients (18.1% vs. 7.5%, P = 0.044). Systemic retinoids were more often used for treatment in the adolescence acne patients than post-adolescence acne patients (23.8% vs. 10.7%, P = 0.027).

CONCLUSION

Acne predominantly affects adolescents but post-adolescence acne is not uncommon. For post-adolescence acne, females predominate over males. Inflammatory and cystic acne tends to be more predominant in post-adolescence acne patients, whereas comedonal acne is more often seen in adolescence acne patients.

Fractionated stereotactic radiotherapy for acoustic neuromas: long-term outcomes

AIMS

Acoustic neuromas are rare, benign intracranial tumours. There are a variety of treatment options, with no clear optimal management strategy and wide variation in treated outcomes. We report the outcomes from a 15 year cohort of patients treated at our centre using fractionated stereotactic radiotherapy (52.5 Gy in 25 fractions).

MATERIALS AND METHODS

We analysed a retrospective case series. Patients were identified from patient records and a retrospective review of case notes and imaging reports was undertaken. We assessed tumour response using RECIST criteria and recorded toxicity. Progression-free survival was estimated using the Kaplan-Meier method. The study was conducted according to the STROBE guidelines.

RESULTS

In total, 93 patients were identified; 83 patients had follow-up data, with a median follow-up period of 5.7 years. The overall control rate using RECIST criteria was 92%. Data on complications were available for 90 patients, with six (7%) experiencing a reduction in hearing, one (1%) developing trigeminal nerve dysfunction and one (1%) a deterioration in facial nerve function. Other toxicities included four (4%) patients who developed hydrocephalus, requiring the placement of a shunt and one (1%) patient who developed radiation brainstem necrosis. After further evaluation this patient was deemed to have been treated within acceptable dose constraints.

CONCLUSION

These data suggest that a good control rate of acoustic neuromas is achievable using fractionated stereotactic radiotherapy to a dose of 52.5 Gy in 25 fractions. Toxicity is considered acceptable but the episode of radiation brainstem necrosis remains of concern and is the subject of further work.

Genetic variants associated with predisposition to prostate cancer and potential clinical implications

Prostate cancer is the commonest cancer in the developed world. There is an inherited component to this disease as shown in familial and twin studies. However, the discovery of these variants has been difficult. The emergence of genome-wide association studies has led to the identification of over 46 susceptibility loci. Their clinical utility to predict risk, response to treatment, or treatment toxicity, remains undefined. Large consortia are needed to achieve adequate statistical power to answer these genetic-clinical and genetic-epidemiological questions. International collaborations are currently underway to link genetic with clinical/epidemiological data to develop risk prediction models, which could direct screening and treatment programs.

Comparative study on a single treatment response to long pulse Nd:YAG lasers and intense pulse light therapy for hair removal on skin type IV to VI – Is longer wavelengths lasers preferred over shorter wavelengths lights for assisted hair removal

OBJECTIVE

To investigate the safety and effectiveness of a long pulsed Nd:YAG (1064nm) laser compared to a shorter wavelength intense pulse light system for assisted hair removal in volunteers with skin type 1V, V and VI.

METHODS

Eleven patients of Fitzpatrick skin type IV-VI were recruited into the study. The area treated included the face (upper lips, chin and jaw area), axillae and legs. One half of the body was treated with the long pulse Nd:YAG laser and the other half was treated with the IPL system randomly under topical anesthesia. Degree of pain experienced during treatment, the treatment outcome and any complications were observed. Patients were reviewed at 2 weeks and 6 weeks post-treatment.

RESULTS

Volunteers generally described pain from the IPL system as "prolonged burning sensation" but tolerable. Pain from Nd:YAG laser treatment was described as "pinprick" and more intense but tolerable. "Slowing of hair growth"was reported with IPL and Nd:YAG, but with a greater effect from Nd:YAG. Sixty-four percent and 73%(8/11) noticed hair reduction <20% after 6 weeks on IPL and Nd:YAG treated side respectively (ns). Post-inflammatory pigmentation occurred in some volunteers on the IPL treated sides whereas this was not seen on any Nd:YAG treated side, and three of these patients experienced blistering, followed by post-inflammatory pigmentation.

CONCLUSION

In our experience the long pulse width 1064 nm Nd:YAG laser, which can penetrate 5-7 mm into the dermis depths to reach the whole length of the hair follicle, would be expected to produce sufficient follicular injury with less epidermal damage in patients with darker skin type compared to shorter wavelength laser and light system.

Study on the efficacy of ELA‐Max (4% liposomal lidocaine) compared with EMLA cream (eutectic mixture of local anesthetics) using thermosensory threshold analysis in adult volunteers

BACKGROUND

ELA-Max and EMLA cream are topical anesthetics that have been shown to have similar anesthetic efficacy in previous studies.

OBJECTIVE

To evaluate the analgesic efficacy of ELA-Max in comparison with EMLA cream using a novel method of thermosensory threshold analysis.

METHODS

A thermosensory analyzer was used to assess warmth- and heat-induced pain thresholds.

RESULTS

No statistically significant difference was found in pain thresholds using either formulation. However, EMLA cream increased the heat-induced pain threshold to a greater extent than ELA-Max. Thermosensory measurement and analysis was well tolerated and no adverse events were encountered.

CONCLUSIONS

EMLA cream may be superior to ELA-Max for heat-induced pain. This study suggests that thermosensory measurement may be another suitable tool for future topical anesthetic efficacy studies.

Prevalence of body dysmorphic features in patients undergoing cosmetic procedures at the National Skin Centre, Singapore

BACKGROUND

Body dysmorphic disorder (BDD) is characterised by an obsessive preoccupation with a slight defect in appearance, and recognition is essential.

OBJECTIVE

To screen by a previously developed questionnaire the prevalence of BDD in an aesthetics clinic in Singapore. This questionnaire has a positive predictive value of 70% and a negative predictive value of 100%; patients answering that they were preoccupied with their appearance and having answered 'yes' in part A, answered 8 further questions (part B) grading the degree of distress (B4) and impairment (B5) of social functioning.

METHODS

The questionnaire was given to 396 patients: 198 attending Mandalay Aesthetics Clinic and 198 controls at a general outpatient clinic. The screen was considered suggestive of BDD if the patients: were preoccupied by their defect (question A) and qualified the degree of stress (question B4) or impairment of functioning (question B5) as moderate to severe.

RESULTS

58.1% of patients undergoing cosmetic procedures answered 'yes' to question A (odds ratio = 18.21, 95% confidence interval = 9.87-33.59). 41.74 and 26.96% of those qualified the distress (question B4) and impairment (question B5) as moderate to severe.

CONCLUSION

A calculated prevalence of 29.4% in an aesthetics centre warrants systematic screening for BDD.

Chronic autoimmune urticaria: where we stand?

It is well-recognized that 30-40% of chronic idiopathic urticaria is autoimmune in nature. Chronic autoimmune urticaria is caused by anti-FcepsilonRI and less frequently, by anti-IgE autoantibodies that lead to mast cell and basophil activation, thereby giving rise to the release of histamine and other proinflammatory mediators. Activation of the classical complement pathway and formation of C5a are important in dermal mast cell activation. C5a is also a neutrophil and eosinophil chemoattractant. Chronic autoimmune urticaria has been found to be associated with autoimmune thyroid disease. The autologous serum skin test is used as a screening test for chronic autoimmune urticaria and has a sensitivity and specificity of about 70 and 80%, respectively. The current gold standard diagnostic test is the basophil histamine release assay. The treatment of chronic autoimmune urticaria, as in chronic idiopathic urticaria, is with H1 antihistamines. Oral corticosteroids may be used during acute flares. Refractory cases have been shown to respond to cyclosporine and other immunomodulators. The prevalence of chronic autoimmune urticaria in Singapore is similar to that reported in Western countries at about 42%. The presence of thyroid autoimmunity appears to be higher than reported, with 22.5% of patients with chronic idiopathic urticaria here, exhibiting presence of thyroid autoantibodies.

Squamous cell carcinoma developing in two Chinese patients with chronic discoid lupus erythematosus: the need for continued surveillance

Squamous cell carcinoma (SCC) is a rare late sequel of chronic discoid lupus erythematosus (CDLE). We report two cases of SCC developing in Chinese patients with CDLE. The first patient had prior biopsies from the same site that showed viral warts and the second patient had multiple histologically confirmed viral warts around the vicinity of the previously excised SCC. In this paper, we emphasize the need to be suspicious of warty lesions on skin afflicted by CDLE, and repeat biopsies should be performed if there is failure to respond to conventional therapy.

A study of natural rubber latex allergens in gloves used by healthcare workers in Singapore

BACKGROUND

Allergy to natural rubber latex (NRL) proteins is a well-recognized health problem among subjects using protective gloves and products made of NRL. There is currently no information on NRL allergen levels in gloves used in Singapore.

OBJECTIVES

This study aims to quantify the amount of specific allergens (Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02) found in rubber gloves used in Singapore. It also aims to determine if these levels are above thresholds that may cause NRL allergy. It also compares the levels of these specific allergens in gloves used for different purposes, namely gloves used for examination purposes or for surgical procedures.

METHODS

Forty-nine rubber gloves were obtained from major hospitals and healthcare departments in Singapore and were analysed for their NRL allergen levels. FITkit, based on the enzyme immunometric assay technique, was used to determine the specific allergen levels of Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 in the gloves.

RESULTS

Examination gloves had higher NRL allergen content compared with surgical gloves, and powdered gloves had higher allergen content compared with nonpowdered gloves. Among the various allergens, Hev b 5 and Hev b 6.02 were present in larger quantities than Hev b 1 and Hev b 3. Only two of 19 (11%) surgical gloves had the sum of the four allergens (Hev b 1, Hev b 3, Hev b 5, Hev b 6.02) in excess of 1 microg g(-1), which is believed to be a clinically relevant threshold. Among the examination gloves, 25 of 30 (83%) exceeded this level.

CONCLUSIONS

This study shows that NRL allergen levels are present in the majority of examination gloves used by healthcare workers in Singapore at levels high enough to cause NRL allergy among sensitized persons. The information can serve as evidence for a possible requirement for manufacturers to produce gloves with low NRL allergen levels and to state the allergen level in gloves in the product information.

Characteristics of Hori naevus: a prospective analysis

BACKGROUND

Acquired, bilateral naevus of Ota-like macules or Hori naevus (HN) is a common dyschromia seen in Orientals. Other than the original report which documented the clinical spectrum in a group of 22 patients, there have not been many epidemiological reports of this condition.

OBJECTIVES

To evaluate the epidemiology and clinical characteristics of HN in Asian patients.

METHODS

A prospective analysis of 161 patients with HN seen from June 2003 to June 2004 was performed.

RESULTS

All 161 patients in the study were women. Patients were Chinese (n = 155), Eurasian (n = 4), Malay (n = 1) and Indian (n = 1). The median age at onset was 30 years. The malar region was the most frequently affected area. Discrete brown macules were the most common early presentation. Confluent slate-grey macules occurred later. Aggravating factors included sun exposure and pregnancy. Sixty-seven patients reported a positive family history.

CONCLUSIONS

We report our data on the largest series of HN in the literature so far. Predisposing factors in our study are Chinese race, female sex and positive family history. HN became progressively more confluent and grey over time, suggesting migration from the epidermis to the deeper dermis. More studies are needed to confirm the pathogenesis.

Latex sensitisation in healthcare workers in Singapore

INTRODUCTION

Epidemiological data on latex sensitisation among Asian healthcare workers is lacking. The aim of the study is to determine the rate of latex sensitisation in our healthcare workers.

MATERIALS AND METHODS

We recruited 313 healthcare workers, of which 46.6% were operating theatre staff and 53.4% were non-operating theatre staff. Seventy-one administrative staff served as controls. All participants answered a self-administered questionnaire relating to latex exposure and glove-related symptoms. Latex sensitisation was determined by skin prick testing to latex and latex-specific IgE detection.

RESULTS

The prevalence of latex sensitisation among healthcare workers was 9.6%, with no difference between operating theatre and nonoperating theatre staff. Glove-related symptoms were reported in 13.7% of all healthcare workers, of which 22.9% were sensitised to latex. Only 26.7% of latex-sensitised healthcare workers had glove-related symptoms while the rest were asymptomatic. The most common symptoms were itch and hand eczema but the most important discriminating symptom was contact urticaria. Personal history of atopy was more common in sensitised healthcare workers (40.0%) compared to non-sensitised workers (31.8%). Only 1 out of 9 (11.2%) symptomatic latex-sensitised subjects had sought previous medical attention for the problem.

CONCLUSIONS

Latex sensitisation among healthcare workers in Singapore should be considered a significant occupational health risk, as it is in the West. Increased screening and awareness of this problem is essential to identify those at risk.

Metal allergy in Singapore

This is a clinical epidemiologic study to determine the frequency of metal allergy among patch-tested patients in the years 2001-2003. The results are compared with those of previous studies. All patients diagnosed as having allergic contact dermatitis in the National Skin Centre, Singapore, from January 2001 to December 2003 were studied retrospectively. The frequency of positive patch tests to the following metals were nickel 19.9%, chromate 5.6%, cobalt 8.2% and gold 8.3%. The frequency of nickel allergy has been steadily rising over the last 20 years. The most common sources of nickel allergy are costume jewelry, belt buckles, wrist watches and spectacle frames. After declining from 1984 to 1990, chromate and cobalt allergies have also been steadily increasing subsequently. The most common sources of chromate allergy were cement, leather and metal objects. Most positive patch tests to cobalt are regarded as co-sensitization due to primary nickel or chromate allergies. There has been a steep increase in positive patch tests to gold from 2001 to 2003, which is difficult to explain because the relevance and sources of such positive patch tests can rarely be determined with certainty. There has been an overall rise in the frequency of metal allergy in the last 20 years.

Darier's disease in Singapore

BACKGROUND

Darier's disease is a rare, dominantly inherited genodermatosis. Although it has been well studied in caucasians, very little is known about the clinical spectrum of this disorder among Asians.

OBJECTIVES

To determine the demographic and clinical profile of Asian patients with Darier's disease.

METHODS

This is a retrospective study of all new cases of Darier's disease seen in our centre over a 20-year period (1982-2002). Results Twenty-four nonrelated cases of Darier's disease were studied. The incidence rate was 3.1 per million per decade. The gender distribution was 19 males and five females, and the ethnic origin was 21 Chinese, two Malays and one Nepalese. The peak age of onset was between 11 and 20 years. Sun exposure exacerbated the disease in 13 of the patients, and three had neuropsychiatric disorders. The disease affected predominantly seborrhoeic areas in 19 patients, flexural in three, acral in one and was segmental in one patient. Hand involvement was common and included palmar pits in nine patients, acrokeratosis verruciformis in four and nail changes in 12 patients. Haemorrhagic macules were not seen. Rare features included oral mucosal lesions (two patients) and guttate leucoderma (three patients). Pathogens involved in cutaneous infections included herpes simplex virus, Staphylococcus aureus, Streptococcus species and Morganella morgani. All patients treated with oral retinoids had improvement of clinical signs. In contrast, the response to topical retinoids was poor.

CONCLUSIONS

Compared with western studies, our results show a similar incidence rate, age of onset, distribution of disease patterns and association with neuropsychiatric disorders. Features that differ include co-occurrence of guttate leucoderma, rarity of acrokeratosis, absence of haemorrhagic macules and poor response to topical retinoids.

Salivary immunoglobulin A and lysozyme in patients with psoriasis

INTRODUCTION

We compared the salivary immunoglobulin A (IgA) and lysozyme concentration and secretion rates among mild and severe psoriasis patients and controls in Singapore.

MATERIALS AND METHODS

Fifty-one psoriasis patients and 24 controls participated in the study. None of the patients were on immunosuppressive therapy. The Psoriasis Area and Severity Index (PASI) was used to assess the severity of psoriasis. Patients were divided into mild and severe groups by the median PASI score. Each subject contributed a 5-minute unstimulated salivary sample. Enzyme-linked immunosorbent assay method was used to determine the salivary IgA and lysozyme levels.

RESULTS

Psoriasis patients had lower concentration and secretion rate of IgA (geometric mean [GM], 97.5 micro g/mL and 32.3 micro g/min) and lysozyme (GM, 127.6 micro g/mL and 42.1 micro g/min) than controls (IgA GM 256.3 micro g/mL, 79.1 micro g/min; lysozyme GM 180.9 micro g/mL, 55.8 micro g/min) [P = 0.000 (IgA concentration), P = 0.000 (IgA secretion rate), P = 0.015 (lysozyme concentration) and P = 0.150 (lysozyme secretion rate)]. However, no significant differences were observed between mild and severe patients for both IgA and lysozyme concentrations and secretion rates. PASI score showed negative, but non-significant, correlations with either log salivary IgA (r = -0.22, P = 0.13) or log lysozyme (r = -0.09, P = 0.53) secretion rates.

CONCLUSION

Psoriasis patients had lower concentrations and secretion rates of salivary IgA and lysozyme compared to controls. However, among patients, the salivary IgA and lysozyme levels are variable and not related to severity of psoriasis.

Comparison of completely versus incompletely excised cutaneous squamous cell carcinomas

INTRODUCTION

This is a retrospective case series of cutaneous squamous cell carcinomas (SCCs) which were incompletely excised in National Skin Centre, Singapore from 1991 to 1995. This study compared the characteristics of completely excised versus incompletely excised cutaneous SCCs.

MATERIALS AND METHODS

All patients with histologically confirmed SCCs were traced from computerised medical database and information regarding patient profile, tumour characteristics, surgical treatment and outcome were collated. All patients were recalled for clinical examination and documentation of cure. Completely excised and incompletely excised SCCs were compared with regards to the patient and tumour characteristics.

RESULTS

There were 57 patients with 63 SCCs who were treated with surgical excision over the 5-year period. Fifty were recalled for physical examination. There were 30 males and 27 females and their mean age was 83.3 years. All except 1 were Chinese of Fitzpatrick skin type 4. One-third of patients had daily or weekly sun exposure in the past and 21.1% had occupational sun exposure; 3.5% had prior arsenic exposure and 3.5% were previously treated with radiotherapy for other malignancies. The mean duration of SCCs was 18.7 months; 7.9% of patients had multiple SCCs and 15.9% had underlying actinic keratoses. The mean diameter of the tumours was 1.97 cm and nearly half were located on the head and neck. All the SCCs were primary and localised to the skin; 84.1% of them were completely excised with a 4 to 6 mm margin. Incompletely excised SCCs were associated with the male sex, larger tumours and tumours on the genitals and lower limbs.

CONCLUSION

In our experience, the tumour clearance rate is 84.1% following conventional excision. Incomplete excision is associated with male sex, larger tumours and those on the genitals and lower limbs.

Laser Doppler perfusion imaging (LDPI) and transepidermal water loss (TEWL) values in psoriatic lesions treated with narrow band UVB phototherapy. Dermal vascularity may be useful indicator of psoriatic activity

OBJECTIVE

This study attempts to objectively measure physiological changes in transepidermal water loss (TEWL), an indicator of skin barrier function and laser Doppler perfusion index (LDPI) an indicator of skin vascularity, of psoriatic skin lesions following treatment to narrow-band ultraviolet B (UVB) phototherapy using the psoriasis severity (PS) score as a measurement of clinical phototherapy response.

MATERIALS AND METHODS

Fourteen patients with established diagnosis of plaque type psoriasis were studied. The patients received narrow band UVB phototherapy 3 times a week until clearance of their psoriasis and the frequencies are reduced as clearance is observed. Two psoriasis plaques ("lesional skin") were used to measure treatment response and another 2 areas of uninvolved ("non-lesional skin") on the corresponding opposite limbs were identified for comparison. PS score, TEWL and LDPI were carried out at baseline (0 week), 2 weeks and 8 weeks during treatment. Measurements were carried out just before each phototherapy session and repeated 1 hour after phototherapy treatment.

RESULTS

The mean PS score decreased by almost 40% after 2 months phototherapy (t = 2.44, P = 0.028). There was no significant difference in PS score between week 0 and week 2, or between week 2 and week 8. After phototherapy, there was no significant difference in LDPI values on the psoriatic lesional skin between week 0 and week 8 or between week 2 and week 8. It appears that phototherapy does not induce inflammation on non-lesional skin to provoke measurable LDPI changes. The mean TEWL values of psoriatic lesional skin were significantly higher than normal skin throughout the study period before and during phototherapy (week 0, t = 5.71, P = 0.000, week 2, t = 9.29, P = 0.00, week 8, t = 6.93, P = 0.000). It appears that the skin barrier function of psoriatic skin improves only minimally as psoriatic lesions improve clinically (as evidenced by the reduction in PS scores) with narrow-band UVB phototherapy, but the dermal vascularity and blood flow and barrier function of the psoriatic skin remained abnormal.

CONCLUSION

It appears that LDPI and TEWL measurement may not be a good surrogate marker of clinical response to narrow-band UVB phototherapy.

Thermosensory abnormalities and blood flow dysfunction in psoriatic skin

BACKGROUND

Accumulating data have shown evidence of involvement of cutaneous nerve fibres and neuropeptides in psoriasis. Although ample evidence of structural and biochemical data exist no studies have been done on assessing the function of small nerve fibres in this disease.

OBJECTIVES

To investigate the function of small nerve fibres in patients with psoriasis between psoriatic plaques and non-involved skin and in comparison with healthy controls.

METHODS

We performed computerized psychophysical thermal sensory testing of warmth, cold and heat pain thresholds and skin blood flow using laser Doppler imaging in psoriatic lesions vs. non-involved skin and healthy skin. We evaluated these parameters before and immediately after barrier perturbation, and 1 week after as a measure of barrier repair.

RESULTS

There is a significantly elevated warm and decreased cold sensation threshold in psoriatic skin compared with non-involved skin and skin of healthy controls in the same sites. These differences were particularly abnormal 1 week poststripping. The warm sensation threshold was significantly elevated in non-involved skin in psoriatics vs. skin of healthy controls after tape stripping. These findings suggest there is an abnormal function of cutaneous nerve fibres in response to trauma to the stratum corneum, which is not limited to the visible plaque but could be generalized and aggravated by stressful events. Skin blood flow was significantly elevated in psoriatic plaques and inversely correlated to warm sensation thresholds while in healthy controls a direct correlation was noted.

CONCLUSIONS

Our data demonstrate an abnormal thermosensory response in psoriasis.

Basal cell carcinoma, squamous cell carcinoma and melanoma of the skin: analysis of the Singapore Cancer Registry data 1968-97

BACKGROUND

There has been an alarming recent increase in skin cancer incidence among fair-skinned populations. Information from Asian populations is less readily available.

OBJECTIVES

This study examines time trends and ethnic differences of skin cancers among Asians in Singapore.

METHODS

Data from 1968 to 1997 was obtained from the Singapore Cancer Registry, a population-based registry. Age-standardized incidence rates (ASRs) and age-adjusted average annual percentage change, using the Poisson regression model, were calculated.

RESULTS

A total of 2650 basal cell carcinomas (BCCs), 1407 squamous cell carcinomas (SCCs) and 281 melanomas were reported. There was an overall increase of skin cancer from 6.0 per 100000 person years (1968-72) to 8.9 per 100000 person years (1993-97). BCC incidence increased 3% annually, melanoma remained constant, and SCC decreased 0.9% annually. BCC ASRs were highest among Chinese, then Malays and Indians. A similar pattern was noted for SCC and melanomas.

CONCLUSIONS

The incidence rates of skin cancer increased in Singapore during the period 1968-97. Fairer-skinned Chinese had a higher incidence of skin cancer.

A retrospective study on the characteristics of androgenetic alopecia among Asian races in the National Skin Centre, a tertiary dermatological referral centre in Singapore

OBJECTIVE

To study the characteristics and psychosocial impact of androgenetic alopecia among Asian races.

METHODOLOGY

A retrospective telephone interview study of patients managed for androgenetic alopecia in 1997 in a tertiary dermatological referral centre in Singapore.

RESULTS

Two hundred and fifty-six patients (111 females and 145 males) were included in the study. Their mean age at presentation was 33.7 years. There were no significant statistical mean age differences among the different races (Chinese, Malay and Indian). The mean duration of disease before consultation was 31.2 months; 33.2 months for males and 28.9 months for females (ns). Almost all patients (96.4%) were socially embarrassed and "unhappy" about their androgenetic alopecia. Most (90.5%) sought treatment for "cosmetic" reason. Slightly more males sought treatment for cosmetic reason than female (P = 0.01). 7.5% were worried about an underlying systemic disease as a cause of their alopecia. A positive family history of androgenetic alopecia was recorded in 58.9% (151/256). Male patients tend to have higher proportion of having a father or male sibling with similar problem, whereas female patients tend to have higher proportion of having a mother or females sibling with androgenetic alopecia. The predominant balding patterns for males were a combination of frontal, bi-temporal recession and vertex thinning (43%, 45% and 55%, respectively). Whereas in females, the predominant presentation was vertex thinning (60%) and, infrequently, frontal and bi-temporal thinning (19% and 15%, respectively). Diffuse pattern was also more predominant in females (28%) compared to males (10%).

CONCLUSIONS

Most patients presented in their thirties with females presenting earlier than males and almost all patients presented for treatment for cosmetic reasons. Patients are generally unhappy about their appearance as a result of their alopecia. A strong positive family history appears to suggest that the disorder may be acquired through an autosomal dominant trait. Male patients tend to have a father or male sibling with similar condition and female patients tend to have a mother or female sibling with similar condition.

A comparison of the combined effect of cryotherapy and corticosteroid injections versus corticosteroids and cryotherapy alone on keloids: a controlled study

BACKGROUND

Treatment modalities for keloids, which are commonly found in Asians, include intralesional corticosteroid injections and cryotherapy as well as a combination of these two modalities. Few studies have been performed in a controlled fashion to evaluate the efficacy of these treatments.

OBJECTIVE

A controlled study, to evaluate the combined effect of intralesional corticosteroid injection with cryotherapy vs. intralesional corticosteroid or cryotherapy alone.

METHODS

Ten patients completed the study: eight patients had at least three keloids and two had two keloids. Patients were treated for at least three sessions 4 weeks apart. The outcome of the lesions was compared between the treatments regarding the thickness of the lesion using a caliper and photographic assessment, and the presence of itch and pain before and after treatment using a visual analogue scale.

RESULTS

In terms of thickness, the keloids responded significantly better to combined cryotherapy and triamcinolone vs. triamcinolone alone or cryotherapy alone (P < 0.001). Pain intensity was significantly lowered with all treatment modalities; however, itch was lowered only with the combined treatment and intralesional corticosteroid alone. No significant side effects were noted with any of the treatments and no re-occurrence of keloids was noted with the combined therapy.

CONCLUSION

Combined injection of intralesional steroids with cryotherapy appears to be superior to other current modalities.

Sexually transmitted diseases in the older population in Singapore

BACKGROUND

Sexually transmitted diseases (STDs) in persons older than 50 years are rarely studied because STDs are more common in young people.

AIM

To study the distribution and types of STDs in older persons, defined in our study as individuals aged 50 years or older.

METHOD

Retrospective analysis of surveillance data for diseases notified under the Infectious Disease Act, which include syphilis, gonorrhoea, non-gonococcal urethritis (NGU), vaginal discharge and chancroid. Human immunodeficiency virus (HIV) infections were not included. Data from notifications of diseases, such as genital herpes and genital warts, which are not compulsory, were also analysed. Period of study was from January 1996 to December 2000.

RESULTS

During the study period, STD notifications for persons aged 50 years and older accounted for 7.6% of all notifications. Among these older persons, males were predominantly affected. The most common disease notified in older persons was gonorrhoea (600 cases), followed by non-infectious syphilis (578 cases) and NGU (339 cases). There were 76 cases of infectious syphilis. The age-specific disease rates for this group of older patients were as follows (number of cases per 100,000 patients per year): gonorrhoea-17.61, non-infectious syphilis-16.96, infectious syphilis-2.23, NGU-20.66, genital warts-6.92 and genital herpes-7.33.

CONCLUSION

Although STDs occur mainly in the young, it affects a small but significant proportion of persons aged 50 years and older. A better understanding of the epidemiology of STDs in these population is important for reducing STD morbidity and improving STD care.

Clinical characteristics of pruritus in chronic idiopathic urticaria

BACKGROUND

Although pruritus is a predominant symptom of chronic idiopathic urticaria (CIU) its clinical characteristics have not been explored.

OBJECTIVES

To characterize the clinical pattern and sensory and affective dimensions of the itch experience, utilizing a comprehensive itch questionnaire.

METHODS

A structured questionnaire based on the McGill pain questionnaire was used in 100 patients suffering from CIU randomly recruited from a tertiary referral centre.

RESULTS

All 100 patients recruited with CIU completed the questionnaire. In 68 patients pruritus appeared on a daily basis. Most patients experienced their pruritus at night and in the evening (n = 83), and 62 reported difficulty in falling asleep. Pruritus involved all body areas, but mostly the arms (n = 86), back (n = 78) and legs (n = 75). Accompanying symptoms were a sensation of heat in 45 patients and sweating in 15. Most patients (n = 98) were prescribed antihistamines (mainly sedating), of whom 34 experienced long-term relief. The sensation of itch was reported to be stinging (n = 27), tickling (n = 25) and burning (n = 23). Seventy-six patients found their pruritus bothersome, 66 annoying and 14 complained of depression. The itch intensity at its peak was more than double that felt after a mosquito bite. The worst itch scores of those who felt depressed were significantly higher than of those who did not (P = 0.018). There was a positive correlation between the sensory and affective scores during worst itch (P < 0.001).

CONCLUSIONS

This study describes the itch experienced in CIU, highlighting sensory and affective dimensions. The itch questionnaire was found to be a valuable tool for evaluating pruritus in CIU and its unique features.

Itch characteristics in Chinese patients with atopic dermatitis using a new questionnaire for the assessment of pruritus

BACKGROUND

Although pruritus is the predominant and commonest feature of atopic dermatitis, its clinical characteristics have not been explored.

OBJECTIVE

To characterize the clinical pattern and sensory and affective dimensions of the itch experience utilizing a comprehensive itch questionnaire.

METHODS

A structured itch questionnaire based on the McGill pain questionnaire was given to 102 Chinese patients with known atopic dermatitis.

RESULTS

There were 100 patients with atopic dermatitis who fully filled the questionnaire. In 87% of the patients pruritus appeared on a daily basis. It had a prolonged duration (mean duration 10.7 7.3 years). It involved all body areas mostly in the lower limbs (83%), flexures (76%), upper limbs (71%) and neck (65%). Itch intensity during its peak was nearly twice higher than the itch of a mosquito bite. Itching was most frequent at night (65%), and 84% of patients reported of difficulty falling asleep. Daily life activities which increased the severity of itch were sweat in 96%, dryness in 71%, stress in 71% and physical effort in 73%. The major factors which were found to reduce the intensity of pruritus included: bathing with cold water in 55% and cold ambient environment in 56%. Associated symptoms were heat sensation (51%), sweating (40%) and pain in the pruritic area (45%). The various anti-pruritic therapies had limited long-term effect. The pruritus was bothersome (52%) and a major distress to the patient. The affective score correlated to itch intensity during its peak (r = 0.4, P < 0.001).

CONCLUSIONS

The study provided a detailed description of pruritus in atopic dermatitis with new data on affective and sensory dimensions and associated symptoms. The questionnaire was found to be a useful tool in characterization of itch.

Laser skin resurfacing treatment outcome of facial scars and wrinkles in Asians with skin type III/IV with the Unipulse CO2 laser system

OBJECTIVE

To study the efficacy and complications from Unipulse CO2 laser resurfacing system (Nidek, California) for the treatment of scars and wrinkles in patients with Type III and IV skin type.

METHODOLOGY

This is a prospective study of patients with skin type III and IV who received laser-resurfacing treatment for facial scars and wrinkles. All patients received topical tretinoin 0.025% cream at least two weeks prior to laser resurfacing. Laser resurfacing was carried out under lidocaine 1% nerve blocks with the Unipulse CO2 laser scanning system. The power at tissue was set at 15 watts (fluence = 6.12 J/cm2; spot size = 1.02 mm, frequency = 300 Hz), with a 20% overlap. Lesions around the eyes were resurfaced with one pass. Those on other parts of the face with two to three passes. Patients were assessed up to 12 months. Treatment response (assessed by patient and dermatologist) was graded as "no change" = no improvement, "minimal improvement" = <25% clearance, "moderate improvement" = 25-50% clearance,"good improvement" = 50-75% clearance and "excellent improvement" = >75% clearance. Complications (assessed by dermatologist only) including erythema, hypopigmentation and hyperpigmentation were scored subjectively as none, minimal, mild, moderate and severe.

RESULTS

16 (nine females, seven males) patients were studied. Thirteen patients were treated for acne scars, two patients for wrinkles and one patient for chicken pox scar. Their mean age was 30.7 years (SD = 9.5 years). Fifteen patients had skin type IV and I had skin type III. TREATMENT RESPONSE: Thirteen patients were assessed at six weeks post laser treatment. One (8%) patient had "minimal improvement" (<25%) improvement, 10 (77%) patients had "moderate improvement" (25-50%) and 2 (15%) patients had "moderate improvement" (50-75%) improvement. At six months, 37% had "minimal improvement", 37% had "moderate improvement" and two had "good improvement and one patient with fine wrinkles had "excellent improvement".

COMPLICATIONS

All patients experienced severe erythema at Day 1. Erythema faded over six months. By three months only 22% had minimal erythema and by six months none had erythema. Moderate pigmentation developed in 15% at six weeks. At three months 33% had varying degree of pigmentation. At six months one (12%) patient had residual pigmentation. Only one patient developed mild minimal hypopigmentation at six month, which cleared at 12 months. Another patient developed hypopigmentation at 12 months.

CONCLUSION

CO2 laser resurfacing provides minimal to moderate improvements for scars and wrinkles among Asians with darker skin type. Erythema fades over six months after resurfacing. Post-inflammatory pigmentation is common but tends to clear over six months.

The effect of topically applied aspirin on localized circumscribed neurodermatitis

BACKGROUND

Lichen simplex chronicus is a troublesome intractable itchy dermatosis, which may persist despite intensive topical treatments. Recently it has been demonstrated that topical aspirin solution with dichloromethane has a significant antipruritic effect in an experimentally induced itch.

OBJECTIVE

The aim of this double-blind, crossover placebo trial was to evaluate the efficacy of this solution in the treatment of lichen simplex chronicus.

METHODS

Twenty-nine patients with lichen simplex chronicus of at least 3 months' duration that did not respond to topical corticosteroids were randomized in a double-blind fashion to receive aspirin/dichloromethane solution in treatment period 1 for 2 weeks followed by placebo in treatment period 2 or placebo followed by aspirin in period 2 with a crossover design after a 2-week washout. The patients rated the pruritus intensity before and during therapy with a visual analog scale; a blinded investigator performed photographic assessment.

RESULTS

A significant therapeutic response was achieved in 11 (46%) of the patients who completed the study compared with 3 patients (12%) receiving placebo. Overall, aspirin-treated patients experienced an average decrease in the visual analog scale of 2.18 +/- 2.86 versus 0.69 +/- 2.31 of those receiving placebo. The difference between the 2 treatments for week 2 was significant (P =.03).

CONCLUSION

The study suggests that topical aspirin/dichloromethane might be a practical treatment for lichen simplex chronicus.

Positive patch-test reactions to para-phenylenediamine, their clinical relevance and the concept of clinical tolerance

406 patients were patch tested over an 18-month period (January 1998 to June 1999) at a dermatology referral centre. 33 patients (8.1%) had a positive reaction to para-phenylenediamine (PPD). 20 patients were experiencing PPD hair dye dermatitis (present relevance, 61%), 2 were using PPD hair dyes without developing dermatitis (clinical tolerance, 6%), 4 had previously used PPD hair dyes with dermatitis in the past (past relevance, 12%), 3 had previously used PPD hair dyes without dermatitis (past exposure, 9%) and 4 had no known exposure to PPD (unknown relevance, 12%). Of the 20 patients whose test results were of present relevance, 17 avoided PPD hair dyes, resulting in total clearance of the dermatitis in all except 3, who had concurrent endogenous eczema. 3 continued using PPD hair dyes: 2 had recurrent contact dermatitis and 1 avoided dermatitis with meticulous technique. The 2 patients with clinical tolerance continued using PPD hair dyes with no dermatitis.

Long-term colchicine for recalcitrant palmoplantar pustulosis: treatment outcome in 3 patients

Palmoplantar pustulosis (PPP) is a chronic, relapsing, pustular eruption affecting the palms and soles for which treatment is often difficult and frustrating. Short-term colchicine has been used to treat PPP with variable response. We report on the successful treatment of 3 patients with severe, therapy-resistant, chronic PPP. We observed significant reduction in the frequency of pustular eruptions and the number of pustules with maximum tolerable doses of colchicine treatment for up to 12 months.

Comparison of allergic contact dermatitis cases in the private and subsidized clinics in the National Skin Centre, Singapore

INTRODUCTION

This is an epidemiologic study to compare allergic contact dermatitis patients in the private and subsidized clinics.

PATIENTS AND METHODS

All patients diagnosed to have allergic contact dermatitis in the National Skin Centre from January 1999 to June 1999 were studied retrospectively.

RESULTS

More private patients were evaluated for allergic contact dermatitis than subsidized patients in the study period (138 vs. 99). The female-to-male ratio in the paying clinics was greater than in the subsidized clinics (3:1 vs. 1:1). The mean age was the same for both groups i.e., 40 years. There was a greater proportion of unskilled workers attending the subsidized clinic (24.2% vs. 5.4%). The mean duration of rash before evaluation was longer for paying patients than for subsidized patients (31 vs. 22 months), but this was not statistically significant. A significant proportion of the patients had a history of atopic disease and endogenous dermatitis. The most frequent sites for allergic contact dermatitis were the face, hands and the exposed areas of the limbs. The most common allergens were nickel, cobalt and fragrance in the paying patients; and nickel, chromate and fragrance in the subsidized patients.

CONCLUSION

More female patients with allergic contact dermatitis and more atopic patients were seen in the private clinics. The forearms, fingers, feet and ears were more commonly affected in the subsidized patients.

Parasitic skin infections in the elderly: recognition and drug treatment

There are many parasitic infections of medical importance, which can produce both systemic disease as well as skin lesions. For the most part, treatment of these infections in the elderly does not differ very much from that of younger patients. However, one must be aware that the geriatric population can present with certain challenges with regard to diagnosis of these diseases because history taking may be more difficult and patients often already have a set of other medical problems, which may overshadow the skin lesions. In addition, the clinical manifestations of these infections may not appear classical and may be altered. Dosages of drugs used to treat these infections, even topical agents, may require adjustments in this population. The recognition of scabies in elderly people living together is important and early treatment with topical scabiecides, including oral ivermectin, will help to control the spread of the infestation. Pediculosis may be a cause of pruritus in the elderly and can be treated with malathione, lindane or permethrin. Less common parasitic infections in the elderly, including cutaneous larva migrans and cutaneous leishmaniasis, present with a characteristic clinical picture and can be effectively treated with oral thiabendazole and intravenous antimonials.

A retrospective review of PUVA therapy at the National Skin Centre of Singapore

BACKGROUND

Photochemotherapy (PUVA) is beneficial for the treatment of various dermatoses. The introduction of ultraviolet B and narrow-band ultraviolet B phototherapy has had a significant impact on the role of PUVA in dermatology. This study aims to assess the current role of PUVA in treating dermatoses, in a predominantly Asian population, at the National Skin Centre in Singapore.

MATERIALS AND METHODS

We reviewed the clinical data of 115 patients who were started on PUVA treatment at the National Skin Centre, Singapore in 1998. We analysed the epidemiology data, the clinical response rate and the adverse effects of PUVA therapy. All of the patients continued to have ongoing maintenance treatment.

RESULTS

Most of our patients were Chinese (74.8%) and male (58.3%), ranging from the ages of 4 to 74 years. Vitiligo (60.9%) was the commonest skin disorder treated with PUVA, followed by psoriasis (20.9%), endogenous eczema (11.3%), mycosis fungoides (3.5%), lichen amyloidosis (2.6%) and prurigo nodularis (0.9%). Most of our patients received paint PUVA (50.4%), 33.9% oral PUVA and 15.7% bath PUVA. The best clinical response--those patients achieving a greater that 50% clearance--was observed in patients with endogenous eczema, psoriasis and mycosis fungoides (76.8%, 73.9% and 60%, respectively). Of the vitiliginous patients, 54.3% experienced a poor response to PUVA therapy. The main side effects were mild erythema and pruritus.

CONCLUSION

PUVA remains a valuable, well-tolerated therapeutic option for a variety of dermatoses.

Malignant melanoma seen in a tertiary dermatological centre, Singapore

INTRODUCTION

Primary malignant melanoma is an uncommon skin tumour in Singapore compared with the Western countries. The clinical characteristics of melanoma have been rarely reported in Asians.

OBJECTIVES

Our purpose was to study the incidence, clinical characteristics and risk factors of biopsy proven malignant melanoma seen in a tertiary referral skin hospital.

METHODS

Case records of patients with histology proven malignant melanoma from January 1989 to December 1998 were retrieved. Patients were interviewed and a complete skin and systemic examination was performed. Data on demographics, histological types, clinical characteristics and risk factors were collated.

RESULTS

Between 1989 and 1998, 27 patients were diagnosed with histology proven malignant melanoma. There was a predominance of Chinese with a female to male ratio of 1.3:1. There was a mean lag period of 1.6 years to diagnosing melanoma and there is a general lack of knowledge among the local patients. Most of the lesions (89%) occurred on the extremities. Acral lentiginous melanoma (41%) and nodular melanoma (41%) were the two commonest histologic types. Of the nodular melanomas, 64% were observed in patients below 50 years (64%) while majority of the acral lentiginous melanomas occurred in those above 50 years (91%). In terms of risk factors, we reported a high prevalence of diabetes mellitus with acral lentiginous melanoma.

CONCLUSIONS

This study highlighted interesting aspects in terms of clinical characteristics and risk factors in our local patients. It also served as a remainder of the need to raise awareness among the public and medical community of skin cancers or melanomas as they are potentially treatable if detected early.

Occupational allergic contact dermatitis in Singapore

Singapore has a resident population of 3,000,000 and a workforce of 1,780,000. Most are employed in manufacturing, services and commerce (245,000). From 1996 to 1998, 3472 cases were notified to the Ministry of Manpower and confirmed as occupational diseases. Noise-induced hearing loss accounted for 82% of cases, while only 11% of cases were industrial dermatitis. Occupational allergic contact dermatitis was not common, comprising approximately one third of the 369 cases of industrial dermatitis that were notified. However, we believe that the majority of cases are not notified to the authorities. The main occupational contact allergens were chromates, nickel, rubber chemicals, cutting fluids and resins. Most affected workers were from the construction, electronics and metalworking industries. Case series of occupational dermatoses among electronics and metal workers have been published. Of the cases of occupational dermatoses among electronics workers seen at a tertiary dermatological centre, 41% of 149 had allergic contact dermatitis (ACD). The commonest allergens were nickel, resins and rubber chemicals. In another case series of 252 metalworkers seen at the same dermatological centre, 23% suffered from ACD. The common allergens were metals and cutting fluids. Besides the common causes of ACD, unusual allergens have also been described. One example is ACD to grasses, which is seen mainly among military personnel. Population studies have been conducted in several industries. A survey of 2567 electronics workers revealed a 2% point prevalence of ACD. Of the occupationally relevant cases, 46 were nickel sensitive, 7 reacted to colophony, and 1 case to epoxy resin. A study of 272 prefabrication construction workers showed a 14% prevalence rate of occupational dermatitis. Of the 38 cases, 42% were ACD to chromates and rubber chemicals. Occupational ACD in Singapore is not as uncommon as the reported statistics suggest. Population-based reports, which overcome the problem of under-notification, show that the prevalence is variable in different industries.

Occupational skin diseases in national servicemen and military personnel in Singapore, 1989-1999

This is a study of occupational skin disease among military personnel and conscripts in Singapore. All military personnel and conscripts diagnosed with occupational dermatoses in the National Skin Centre, Singapore, between 1989-1999 were studied retrospectively. Conscripts and regulars comprised 7.3% of all occupational skin disease patients seen. All were male, with a mean age of 23 years. Irritant contact dermatitis was more common than allergic contact dermatitis, by 4.4:1. The most common vocations associated with occupational skin diseases are those involving vehicle repairs and maintenance (48%) and food handling (19%). The most common irritants were oil/grease (66%), wet work (23%) and solvents (18%). The most common allergens were food (40%) and chromates (20%). Military personnel and conscripts make up a significant proportion of occupational skin disease patients seen in Singapore.

Occupational skin diseases in national servicemen and military personnel in Singapore, 1989-1999

This is a study of occupational skin disease among military personnel and conscripts in Singapore. All military personnel and conscripts diagnosed with occupational dermatoses in the National Skin Centre, Singapore, between 1989-1999 were studied retrospectively. Conscripts and regulars comprised 7.3% of all occupational skin disease patients seen. All were male, with a mean age of 23 years. Irritant contact dermatitis was more common than allergic contact dermatitis, by 4.4:1. The most common vocations associated with occupational skin diseases are those involving vehicle repairs and maintenance (48%) and food handling (19%). The most common irritants were oil/grease (66%), wet work (23%) and solvents (18%). The most common allergens were food (40%) and chromates (20%). Military personnel and conscripts make up a significant proportion of occupational skin disease patients seen in Singapore.

Antibiotic sensitivity of Propionibacterium acnes isolates from patients with acne vulgaris in a tertiary dermatological referral centre in Singapore

OBJECTIVES

To study the minimum inhibitory concentrations (MICs) of Propionibacterium acnes (P. acnes) isolates to selected antibiotics from patients with acne vulgaris in Singapore and determine if resistance increases with prolonged use of antibiotics.

DESIGN

A single-centre prospective study.

SETTING

Tertiary dermatological referral centre in Singapore.

PATIENTS

One hundred and fifty patients with acne vulgaris seen at the National Skin Centre.

RESULTS

In patients who had never been on antibiotics, there were no resistant isolates of P. acnes. In patients who had been on short-term antibiotics (between 6 to 18 weeks), there were 2 resistant strains among the 34 isolates (6.25%); in patients who had been on antibiotics for longer periods, there were 11 resistant strains among the 51 isolates (21.6%). The differences in the rates of isolation of resistant strains between patients who had not been on antibiotics to those that had been on long-term antibiotics were statistically significant (P = 0.015). There was also a significant difference in isolation of resistant strains from those on short-term antibiotics compared to those who had been on long-term antibiotics (P = 0.036). Resistance to erythromycin was most commonly encountered. Most of the erythromycin-resistant strains also showed cross-resistance to clindamycin. The average MICs to antibiotics such as minocycline, erythromycin and clindamycin in those on long-term antibiotics were significantly higher when compared to patients who had not been on antibiotics.

CONCLUSIONS

Antibiotic resistance in P. acnes isolates in Singapore follows similar patterns to studies conducted in Europe. Resistance to erythromycin was most commonly seen, and this is associated with cross-resistance to clindamycin. Among the tetracycline group of drugs, the average MICs to tetracycline was higher than that for doxycycline, which in turn was higher than that for minocycline. Antibiotic resistance can occur with short-term antibiotic courses, and the rate of resistance increases as the duration of antibiotic consumption increases.

Clinical utility of polymerase chain reaction in the detection of Mycobacterium tuberculosis in different types of cutaneous tuberculosis and tuberculids

INTRODUCTION

The role of polymerase chain reaction (PCR) in the diagnosis of cutaneous tuberculosis in clinical practice has not been defined as no PCR assay has been tested in a large-scale clinical study. The objective of this study was to test the clinical utility of a PCR assay in the diagnosis of different types of cutaneous tuberculosis and tuberculids.

MATERIALS AND METHODS

Analysis of archival biopsy specimens by a nested PCR assay targeting IS6110 of Mycobacterium tuberculosis (M. tb) DNA was performed in a tertiary-care skin hospital in Singapore. PCR results were compared with cultures and concordance with final diagnosis. PATIENTS AND SPECIMENS: One hundred and nineteen skin biopsies from 105 patients comprising 58 cases of confirmed or highly probable cutaneous tuberculosis, ranging from multibacillary infections to paucibacillary forms and 47 cases of possible tuberculids were analysed. Twenty-four subjects with non-tuberculous granulomas and normal skin controls were included.

RESULTS

In 14 immunocompromised patients with multibacillary mycobacterial infections (AFB+ on biopsy), PCR was positive in 9 patients. Correlating PCR results with the final diagnosis, the PCR technique was 100% sensitive and specific in this group. In paucibacillary tuberculosis, PCR positivity rates were 55% for tuberculosis verrucosa cutis (38 cases) and 60% for lupus vulgaris (5 cases). When confirmed cases of tuberculosis were considered, the overall sensitivity was 73%. In 26 cases of erythema induratum, PCR was positive in 54% and correlated with a documented response to anti-tuberculous treatment in 80%.

CONCLUSIONS

The use of PCR in the routine diagnostic panel for cutaneous tuberculosis should take into consideration the differential sensitivities for different clinical types. In the setting of an immunocompromised patient with AFB+ lesions, PCR has a definite role in rapid diagnosis and in differentiating atypical mycobacterial infection from tuberculosis. Where paucibacillary tuberculosis is suspected, clinical decision should not be based on PCR results alone. In erythema induratum, we found some correlation between PCR results and response to anti-tuberculous therapy.

Epidemiology of eczematous cheilitis at a tertiary dermatological referral centre in Singapore

In a retrospective epidemiologic study of 202 patients with eczematous cheilitis attending a patch test clinic, females (182 (90%)) predominated over males (20 (10%)). The mean age of our patients was 30.9 years. There was no significant difference between the mean age of females (31 years) presenting with cheilitis compared to males (29 years). Endogenous cheilitis (53%) was the commonest diagnosis, followed by allergic contact dermatitis (34%) and irritant contact dermatitis (5.4%). A personal history of atopy was recorded in 33%. There was no significant difference in the prevalence of atopy between the sexes or among the diagnoses. The mean duration of cheilitis was 16.4 months. The duration was significantly longer in males (29 months) than in females (15 months) (p=0.004). The mean number of positive patch test reaction in patients with allergic contact cheilitis (2.8) was significantly higher than in those with irritant contact cheilitis (0.2) (p = 0.012) or endogenous cheilitis (0.5) (p = 0.00). The commonest cause of allergic contact cheilitis were lip cosmetics, including lipsticks and lipbalms, followed by toothpastes. The commonest cause of irritant contact cheilitis was lip-licking, lipsticks and medication. In 81/202 (40%) patients, 1 or more causes of contact cheilitis could be ascertained. In females, lip cosmetics were the commonest cause, accounting for 54% (44/81) of cases. Toothpastes accounted for 21% (17/81), followed by topical medication 7% (6/81). For males, toothpastes were the commonest cause of allergic contact cheilitis. Ricinoleic acid and the patient's own lip preparations were the commonest relevant contact allergens.