Comparative frequency of patch test reactions to topical antibiotics

Synergistic activity of clioquinol with voriconazole and amphotericin B against fungi of interest in eye infections

Keratoplasty represents a risk factor for fungal eye infections, despites the antibacterial actives in the corneal tissue preservation means, it does not contain active substances with antifungal action. Among the most commonly associated fungal agents are the species belonging to the genera Fusarium and Candida. These agents can trigger an infectious process characterized by swift progression associated with high rates of morbidity, causing irreversible damage. Polyene and azole antifungals are the main agents of ocular therapy, however, they demonstrate some limitations, such as their toxicity and fungal resistance. In this context, drug repositioning and the combination of antifungals may be an alternative. Hence, the goal of this study was to investigate the potential activity of clioquinol (CLQ), a derivative of 8-hydroxyquinoline with previously described antifungal activity, along with its triple and quadruple combinations with antifungal agents commonly used in ophthalmic fungal therapy, natamycin (NAT), voriconazole (VRC), and amphotericin B (AMB), against main fungal pathogens in eye infections. The MICs for CLQ ranged from 0.25 to 2.0 μg/mL, for NAT from 4.0 to 32.0 μg/mL, for AMB it ranged from 0.25 to 16.0 μg/mL and for VRC from 0.03125 to 512.0 µg/mL. Among the tested combinations, the VRC-AMB-CLQ combination stands out, which showed a synergistic effect for more than 50 % of the tested strains and did not present antagonistic results against any of them. Toxicity data were similar to those antifungals already used, even with lower potential toxicity. Therefore, both clioquinol and the triple combination VCR-AMB-CLQ exhibited promising profiles for use as active components in corneal tissue preservation medium.

Contact Dermatitis in Children

Contact dermatitis (CD) is commonly encountered in the pediatric population. Allergic and irritant are the two forms of CD and both cause significant clinical problems in children, but they are often underrecognized. The skin lesions in CD may be polymorphic and closely mimic other common pediatric skin diseases. The diagnosis usually requires patch testing after obtaining a detailed history and performing a physical examination. Metals, fragrances, and certain preservatives are the most common causative agents in children. This article discusses the pathophysiology, diagnosis, and management of this common skin condition in the pediatric population. [Pediatr Ann. 2021(5):e198-e205.].

Evaluation of activity and toxicity of combining clioquinol with ciclopirox and terbinafine in alternative models of dermatophytosis

Dermatophytosis is a superficial fungal infection that affects humans and is very common in small animals. The treatment using the most commonly used antifungals is failing, and new therapeutic alternatives are required to combat the resistance of these fungal infections. Previous studies by the group have shown that clioquinol is an important therapeutic alternative in the treatment of dermatophytosis. The object was to conduct studies of antidermatophytic activity and the irritant potential from the double and triple combinations of clioquinol, terbinafine and ciclopirox in ex vivo and in vivo alternative models. To evaluate the irritant potential of antifungal combinations, the alternative HET-CAM method (chicken egg test chorioallantoic membrane) was used. Ex vivo models were used to assess the effectiveness of antifungal combinations, using pig hooves and veterinary fur. Any possible tissue damage was to assess through in histopathology of swine ears. HET-CAM results showed that all combinations can be classified as non-irritating, corroborated by the results of the histopathological evaluation of the pig's ear skin. Only the double combinations managed to remove 100% of the colony-forming units (CFU) formed on the pig's hooves. The clioquinol + terbinafine combination and the triple combination were more effective than clioquinol + ciclopirox in eradicating the preformed biofilm in fur of veterinary origin. These results show the potential of formulations of clioquinol in combination with antifungals for use in humans and in the veterinary field to combat dermatophytosis, as an important alternative therapy, for use in the near future.

Topical Antibacterials in Dermatology

Topical antibacterials are commonly used for superficial pyodermas such as impetigo and treatment or prevention of infections following minor cuts, abrasions, burns, and surgical wounds. Several antibiotics and antiseptics are available for use in different indications. One of the major uses of topical antibacterials is acne in which benzoyl peroxide is the drug of the first choice either singly or in combination with antibiotics or retinoids. Mupirocin and fusidic acid are the two most commonly used antibiotics for the treatment of superficial pyodermas and eradication of staphylococcal carrier state. Bacterial resistance to topical antibiotics is a growing concern and topical antiseptics such as gentian violet are getting renewed interest as alternatives. Incidence of contact dermatitis is a limiting factor for the use of several topical antibacterials. Although many botanical products have demonstrated in vitro activities against skin pathogens, their clinical utilities remain to be established by good-quality clinical trials.

Clinicoepidemiological and Patch Test Profile of Patients Attending the Contact Dermatitis Clinic of a Tertiary Care Hospital in North India: A 7-Year Retrospective Study

Introduction:

Allergic contact dermatitis (ACD) is a growing concern due to increased use of cosmetics and topical medications routinely and exposure to a large number of allergens on day-to-day basis. Patch testing is a reliable method for detecting the causative antigens in suspected cases.

Aims and Objectives:

To assess the demographic profile, pattern of ACD, and patch test profile of suspected cases of ACD attending contact dermatitis clinic of our department.

Materials and Methods:

It was a retrospective study in which all the data enrolled in the contact dermatitis clinic of our department over a 7-year period were analyzed. Patch testing was done using the Indian Standard Series of 20 antigens primarily, and other batteries were used depending on patient requirement and availability.

Results:

A total of 582 patients were enrolled in the contact dermatitis clinic over a period of 7 years. Hand eczema was the most common pattern seen in 268 cases followed by feet eczema, hand and foot eczema, facial eczema, forearm and leg eczema and photoallergic contact eczema. A total of 177 patients (30.4%) gave positive patch test results, with nickel sulfate being the most common allergen identified followed by potassium dichromate, cobalt sulfate, paraphenylenediamine, neomycin sulfate, and fragrance mix.

Conclusion:

Common allergens identified in our study were more or less similar to studies from other parts of India. However, due to the unique climate of the valley, the profile of parthenium sensitivity was low in our study when compared to the rest of the country.

Decreasing Rates of Neomycin Sensitization in Western Canada

Background:

Neomycin contact sensitization rates in North America range from 7% to 13%, whereas in Europe they average approximately 1.9%.

Objectives:

Given that topical neomycin products are no longer readily available in Canada, the aim of this study was to examine what influence this may have had on neomycin sensitization rates in the 3 western provinces.

Methods:

On the basis of an observation originally communicated by L. M. Parsons and C. Zhang of the University of Calgary, which suggested significantly reduced rates of neomycin sensitization in Calgary, Alberta, Canada, a multicenter study of patch test results from 5690 patient charts was undertaken. Data from 3 other western Canadian Universities (the University of Saskatchewan, the University of Alberta, and the University of British Colombia) were analyzed. Data were available from 2001 to 2013 for the University of Saskatchewan (except 2006), whereas the University of Alberta and the University of British Columbia had data from 2009 to 2013. Descriptive statistics, trend analysis, and risk estimates were determined using SPSS version 20.

Results:

Sensitization rates for neomycin have decreased in western Canada and are now similar to those of Europe.

Conclusions:

This trend is likely influenced by the reduced availability of over-the-counter and prescription neomycin products in Canada.

Contact Allergens Causing Hand Eczema in Ethnic Kashmiri Population: A Study of 7-years

BACKGROUND

Hand eczema is one of the commonest eczemas encountered in dermatology practice. Contact allergens responsible for causing hand eczema vary from one geographical area of the world to another.

AIM

The study tries to identify the commonest allergens causing hand eczema in ethnic Kashmiri population.

MATERIAL AND METHODS

A total of 800 patients were patch tested at a sole patch testing facility for the local population over a 7-year period out of which 278 were diagnosed with hand eczema. The morphological type of hand eczema was noted and the patch testing results were analyzed. Past or present relevance of the patch-test result to the clinical diagnosis was also analyzed.

RESULTS

Hand eczema was the most common type of eczema patch tested over the 7-year period, constituting 34.75% of the patch-tested population. A positive patch-test result was obtained in 135 patients (48.5%) out of which it was found to be clinically relevant in about 65% cases. Nickel and potassium dichromate were found to be the two commonest allergens causing hand eczema in our population with positive patch test reactions in 45 and 27 patients respectively. Females showed a much higher incidence of hand eczema as well as higher patch test positivity than males (54.1% vs. 38.1%).

CONCLUSIONS

Hand eczema with a positive patch-test report was found to be much more common in females than males and nickel and potassium dichromate were seen to be the commonest allergens causing hand eczema in ethnic Kashmiri population.

[Lethal Lyell's syndrome induced by fusidic acid]

BACKGROUND

Herein, we report the first case of toxic epidermal necrosis due to oral fusidic acid having a fatal outcome.

PATIENTS AND METHODS

An 82-year-old woman was referred to our dermatology department for generalized bullous skin eruption. Clinical examination showed fever, oral and ocular ulcerations, and epidermal detachment involving more than 70 % of her body surface area together with a positive Nikolsky sign. Lyell's syndrome was diagnosed. Cutaneous histology showed total epidermal necrosis and a normal dermis. Oral fusidic acid had been prescribed 12 days earlier for a chronic sacral pressure sore. No other treatment had been introduced during the previous two months. The outcome was fatal within 24 hours.

DISCUSSION

Fusidic acid is commonly used topically by dermatologists for limited staphylococcal skin infections. Oral treatment is rare and is recommended only for skin, bone or joint infections. This is the first reported case of toxic epidermal necrolysis due to oral fusidic acid. The French national drug safety monitoring register contains only one case in which fusidic acid was a possible culprit.

CONCLUSION

Fusidic acid must be considered a potential source of serious cutaneous adverse reactions, particularly toxic epidermal necrolysis.

Retrospective Clinical Trial of Fusidic Acid versus Petrolatum in the Postprocedure Care of Clean Dermatologic Procedures

BACKGROUND

Clean dermatologic procedures create wounds with a low risk of infection (usually up to 5%). Whether the use of topical antibiotics is advocated, with regard to its efficacy and safety issues such as antibiotic resistance and sensitizing potential, is controversial. Fusidic acid, a topical antibiotic against gram-positive bacteria, is a rare sensitizer and commonly used in postprocedure care in Korea.

OBJECTIVE

This is a retrospective study aimed at comparing the efficacy and safety between fusidic acid and petrolatum for the postprocedure care of clean dermatologic procedures.

METHODS

Patients were treated with either fusidic acid or petrolatum ointment, applied on the wound created during clean dermatologic procedures such as biopsy of the punch, incisional, excisional, and shave types. The efficacy, adverse events, and subjective level of satisfaction were retrieved from medical records.

RESULTS

A total of 414 patients with a total of 429 wounds were enrolled. The overall rate of adverse events was 0.9%, and the rates of adverse events in the fusidic acid group and the petrolatum group were 1.4% and 0.5%, respectively (p=0.370). There was no wound discharge, pain, tenderness, swelling, induration, or dehiscence in both groups. The patients' self-assessment of the wound was not significantly different between the two treatment groups.

CONCLUSION

Our findings support the hypothesis that the routine prophylactic use of topical antibiotics is not indicated for clean dermatologic procedures. We recommend the use of petrolatum in the postoperative care of clean dermatologic procedures because of its equivalent efficacy and superior safety profiles.

Topical Antibacterial Agents in Dermatology

Topical antibacterials are being widely used for the treatment or prevention of superficial bacterial infections. Emergence of drug resistant mutant strains of microorganisms and development of irritant and allergic contact dermatitis is a common problem with many of the topical antibacterials. Topical antibacterials are being reviewed with special emphasis on their spectrum of activity, resistance patterns, contact sensitivity potential and clinical uses. Factors which help the physician to choose a particular antibacterial for the specific indication in order to have the maximum efficacy and minimum adverse effects are discussed.

Anaphylaxis to topically applied sodium fusidate

Fusidic acid is a bacteriostatic antibiotic that is effective primarily on gram-positive bacteria, such as Staphylococcus and Corynebacterium species. It is often topically applied to the skin, but is also given systemically as a tablet or injection. Allergic contact dermatitis, or urticaria, has been reported as a side effect of fusidic acid treatment, whereas anaphylaxis to topically administered fusidic acid has not been reported previously. A 16-year-old boy visited an outpatient clinic for further evaluation of anaphylaxis. He suffered abrasions on his arms during exercise, which were treated with a topical ointment containing sodium fusidate. Within 30 minutes, he developed urticaria and eyelid swelling, followed by a cough and respiratory difficulty. His symptoms were relieved by emergency treatment in a nearby hospital. To investigate the etiology, oral provocation with fusidate was performed. After 125 mg (1/2 tablet) of sodium fusidate was administered, he developed a cough and itching of the throat within 30 minutes, which was followed by chest discomfort and urticaria. Forced expiratory volume in 1 second (FEV1) dropped from 4.09 L at baseline to 3.50 L after challenge, although wheezing was not heard in his chest. After management with an inhaled bronchodilator using a nebulizer, chest discomfort was relieved and FEV1 rose to 3.86 L. The patient was directed not to use fusidate, especially on abrasions. Here we report the first case of anaphylaxis resulting from topical fusidic acid application to abrasions.

Assessing the contributions of the LiaS histidine kinase to the innate resistance of Listeria monocytogenes to nisin, cephalosporins, and disinfectants

The Listeria monocytogenes LiaSR two-component system (2CS) encoded by lmo1021 and lmo1022 plays an important role in resistance to the food preservative nisin. A nonpolar deletion in the histidine kinase-encoding component (ΔliaS) resulted in a 4-fold increase in nisin resistance. In contrast, the ΔliaS strain exhibited increased sensitivity to a number of cephalosporin antibiotics (and was also altered with respect to its response to a variety of other antimicrobials, including the active agents of a number of disinfectants). This pattern of increased nisin resistance and reduced cephalosporin resistance in L. monocytogenes has previously been associated with mutation of a second histidine kinase, LisK, which is a predicted regulator of liaS and a penicillin binding protein encoded by lmo2229. We noted that lmo2229 transcription is increased in the ΔliaS mutant and in a ΔliaS ΔlisK double mutant and that disruption of lmo2229 in the ΔliaS ΔlisK mutant resulted in a dramatic sensitization to nisin but had a relatively minor impact on cephalosporin resistance. We anticipate that further efforts to unravel the complex mechanisms by which LiaSR impacts on the antimicrobial resistance of L. monocytogenes could facilitate the development of strategies to increase the susceptibility of the pathogen to these agents.

Contact sensitization in the elderly

Contact dermatitis from irritant and allergic sources is the reason for 6% to 10% of all dermatologic visits with considerable morbidity and economic impact. Allergic contact dermatitis is a T-cell-mediated inflammatory reaction and develops in predisposed individuals as a consequence of environmental exposure to allergens. Aging is correlated with the rate and type of contact sensitization because of "immunosenescence." The number of old people is growing around the world. This contribution reviews the main findings from published epidemiologic studies on contact allergy in elderly populations. In all examined studies, patch testing was performed in patients with cutaneous manifestations possibly related to contact dermatitis; the prevalence of contact dermatitis in the elderly was from 33% to 64%. Establishing the most frequent allergens responsible for allergic contact dermatitis in the elderly is a hard task. The commonest allergens reported were nickel sulfate, fragrance mix, diamino diphenylmethane, lanolin alcohols, paraben mix, Euxyl K400, quinoline mix, and balsam of Peru. We emphasize that allergens surveillance is needed to realize an "elderly series" for having a useful adjunct to contact allergy that may help the treatment of each patient.

Contact dermatitis in children

Contact dermatitis in pediatric population is a common but (previously) under recognized disease. It is usually divided into the allergic and the irritant forms.

The diagnosis is usually obtained with the patch test technique after conducting a thorough medical history and careful physical examination but patch testing in infants may be particularly difficult, and false-positive reactions may occur.

This study also provides an overview of the most common allergens in pediatric population and discusses various therapeutic modalities.

Allergic contact dermatitis to topical antibiotics: Epidemiology, responsible allergens, and management

Topical antibiotics are widely used to treat cutaneous, ocular, and otic infections. Allergic contact dermatitis to topical antibiotics is a rare but well-documented side effect, especially in at-risk populations. The purpose of this article is to review the epidemiology, responsible allergens, and management of allergic contact dermatitis to topical antibiotics.

LEARNING OBJECTIVE

After completing this learning activity, participants should be able to describe the epidemiology of allergic contact dermatitis related to topical antibiotics; show knowledge of the most common allergenic topical antibiotics; and understand the allergenic cross-reactivity pattern amongst topical antibiotics.

Evaluation and management of pediatric drug allergic reactions

Drug allergy is a common reason for consulting an allergist. Determining whether a particular drug is involved can be accomplished with a careful history and physical examination, knowledge of the common and idiosyncratic reactions of the drugs in question, and selective skin testing. If a drug reaction is suspected, alternatives exist to allow continued appropriate treatment. A practical approach to the pediatric patient is outlined along with a general discussion of common drug allergic reactions encountered in clinical practice.

20 Years of standard patch testing in an eczema population with focus on patients with multiple contact allergies

Results of standard patch tests performed with the same methodology in one centre are rarely available over a large time span. This gives the unique opportunity to study not only prevalence but also persistency of contact allergy and characterize subpopulations. The objectives were to investigate sensitivity rates and persistencies of patch test results and characterize patients with multiple contact allergies. A 20-year retrospective database-based study of 14 998 patients patch tested with the European Standard Series was performed. 34.5% were sensitized, primarily women. Sensitivity to nickel was most frequent and least frequent to mercaptobenzothiazole, N-isopropyl-N-phenyl-p-phenylenediamine and benzocaine. Yearly proportion of negative, mono/double-allergic, and multiple-allergic cases remained stable. Persistency of positive reactions was high for para-phenylenediamine, Cl(Me)isothiazolinone, and primin and poor for paraben mix. 5.1% were multiple allergic, primarily women, and 90% got diagnosed by the first test. Frequency of multiple allergies increased with age. More multiple- than mono/double-allergic patients were tested multiple times. Persistency and sensitivity rates in a Danish eczema population are provided and are useful for decisions regarding the standard series. Patients with multiple contact allergies are typically elderly women who might have long-lasting and hard-to-treat eczema. Cumulative environmental exposure seems necessary to develop multiple allergies.

Contact allergy to topical medicaments becomes more common with advancing age: an age-stratified study

Eczema is common in the elderly people who often use topical medicaments. Previous studies in the elderly people have noted allergic positive patch tests in between 43% and 64% of those tested. We set out to assess whether medicament contact allergies are more common in elderly patients. We undertook a retrospective age-stratified study of all patients patch tested at the Royal Hallamshire Hospital, Sheffield, between January 1994 and July 2005. We confirmed that contact allergy to topical medicaments is more common in those aged more than 70 years compared with the younger age groups. There was no sex difference. The commonest problematic allergen types found in medicaments were fragrances and preservatives. The most frequent individual allergens were fragrance mix, Myroxylon pereirae, lanolins, local anaesthetic agents, neomycin and gentamicin, and tixocortol pivolate. The pattern of medicament contact allergens was similar to that of the younger age groups except that multiple allergic positives were more frequent and sensitivities to local anaesthetics and Myroxylon pereirae were proportionally more common. Elderly patients were more likely to have multiple contact allergies than the younger ones. Care needs to be taken when prescribing topical medicaments to elderly patients with eczema, especially for preparations that contain perfumes, lanolins, and local anaesthetics.

The Influence of Local Instillation of Fusidic Acid on the Development of Microbial Complications After Lung Resection

The efficacy of local instillation of fusidic acid in the prevention of post-surgical microbial complications during various types of lung resection was studied. Four hundred ninety two consecutive patients who underwent 504 thoracotomies for non-small cell lung carcinoma during April 1998-May 2004 were reviewed. The 290 patients of the first period who underwent 298 thoracotomies received a chemoprophylactic regimen of intravenous cefuroxime while the 202 patients of the second period who underwent 206 thoracotomies were additionally treated with fusidic acid, irrigated with local instillation into the pleural space, for the prevention of postoperative septic complications. Patients were followed postoperatively for development of septic complications (empyema and bronchopleural fistula) as well as of pneumonia and wound infection. Seventeen patients (5.7%) of the first period developed empyema and 13 fistula (4.4%), whereas only 2 patients (1.0%) of the second period developed empyema and fistula (OR = 5.876; 95% CI, 1.343- 25.716; P = 0.008 and OR = 4.193; 95% CI, 1.003-20.130; P = 0.034, respectively). Cases of pneumonia decreased, but not significantly, from 21 (7.0%) during the first period to 9 (4.4%) during the second period (OR = 1.613; 95% CI, 0.724-3.593; P = 0.257) while cases of wound infection decreased significantly from 19 (6.4%) to 2 (1.0%) (OR = 6.567; 95% CI, 1.513-28.510; P = 0.003). During the first period 23 pathogens were found from cases of empyema and 73 pathogens from cases of pneumonia and wound infection, whereas during the second period 3 and 18 pathogens were respectively found (OR = 5.3; 95% CI, 1.570-17.888; P = 0.003, and OR = 2.804; 95% CI, 1.628-4.838; P <0.001, respectively). These results indicate that local instillation of fusidic acid in the pleural space prior to lung resection seems effective in reducing the rate of septic complications as well as of wound infections.

Gentamicin Ointment versus Petrolatum for Management of Auricular Wounds

BACKGROUND

Surgeons frequently create defects on the ear in the treatment of cutaneous malignancies. Potentially significant complications of second-intention healing on the ear are suppurative and inflammatory chondritis. Consequently, many physicians advocate the use of oral or topical prophylactic antibiotics after auricular surgery.

OBJECTIVE

The purpose of this study is to compare the efficacy of gentamicin ointment with that of petrolatum for the prevention of suppurative chondritis during second-intention healing of auricular wounds after Mohs surgery.

METHODS

One hundred forty-two patients with a total of 147 second-intention wounds were prospectively selected to receive either gentamicin ointment or petrolatum postoperatively.

RESULTS

One hundred forty-four wounds were evaluated in a follow-up examination or by telephone interview. Eight (5.56%) wounds developed suppurative chondritis. Four wounds received gentamicin and four received petrolatum, for incidences of 4.76% and 6.67%, respectively. Twelve (8.33%) other wounds developed inflammatory chondritis. Ten (11.90%) received gentamicin and two (3.33%) received petrolatum.

CONCLUSIONS

There is no statistically significant difference between the use of gentamicin ointment and petrolatum in the prevention of postoperative auricular suppurative chondritis. The data also demonstrate a disproportionate number of cases of inflammatory chondritis in the gentamicin-treated group. This study supports the cost-effective and potentially less irritating use of petrolatum for wound care in this difficult to manage area.

Contact dermatitis to quinoline, corticosteroids and antibiotics after short time treatment of delayed wound healing following malignant melanoma excision in a young woman

BACKGROUND

We describe a 20-year old woman with retarded healing after a melanoma excision. After short time application of several creams containing antiseptic, antibiotic and anti-inflammatory ingredients she developed a severe contact dermatitis. Patch testing revealed sensitizations against corticosteroids, an antibiotic and quinoline.

CONCLUSION

In our case multiple relevant contact sensitizations appeared within a short period of two months after excision of a malignant tumour.

Rifaximin, a Peculiar Rifamycin Derivative: Established and Potential Clinical Use Outside the Gastrointestinal Tract

Rifaximin is a poorly absorbed semisynthetic rifamycin derivative with a broad spectrum of antibacterial activity including Gram-positive and Gram-negative bacteria, both aerobes and anaerobes. Although originally developed for the treatment of infectious diarrhea, the appreciation of the pathogenic role of gut bacteria in several organic and functional gastrointestinal diseases has increasingly broadened its clinical use. The availability of a topical formulation (a cream containing 5% of the drug) and the lack of transcutaneous absorption pointed out in both animal and human studies has allowed its topical use in skin infections. Furthermore, since the spectrum of antibacterial action of rifaximin includes many organisms (e.g. Bacteroides bivius-disiens, Gardnerella vaginalis, Haemophilus ducreyi) causing genital infections, including Trichomonas vaginalis and Chlamydia trachomatis, its local application in the treatment of bacterial vaginosis (BV) has been attempted. Finally, since periodontal disease, caused by plaque (an aggregate of various bacteria), can be considered a 'local' infection, intrapocket rifaximin was tried in the treatment of periodontal infections. While the efficacy in pyogenic infections of the skin has been confirmed by several investigations, which showed an improvement of both subjective and objective parameters significantly better than that of the reference drug (i.e. chlortetracycline or oxytetracycline), the usefulness of rifaximin in BV and periodontal disease needs to be further studied in well-designed clinical trials.

Contact allergy to neomycin sulfate: results of a multifactorial analysis

PURPOSE

To perform a comprehensive, multifactorial analysis of potential risk factors (demographic and clinical) for contact allergy to neomycin sulfate, a common adverse reaction resulting from the topical use of this drug; especially in some subgroups of the population.

METHODS

Retrospective analysis of allergy test data of the Information Network of Departments of Dermatology (IVDK, www.ivdk.org) between 1998 and 2003, including all patients patch tested with a standard screening series because of suspected allergic contact dermatitis (ACD). As one outcome, a positive (allergic) test reaction to neomycin sulfate was considered. An alternative outcome included only those patients with a positive test to neomycin sulfate and a final diagnosis of ACD. The association between outcome and potential risk factors was analyzed with Poisson regression analysis, deriving prevalence ratios (PR) as risk estimates.

RESULTS

Of the 47,559 patients tested, 2.5% had positive reactions to neomycin sulfate, while in 1.1% ACD was additionally diagnosed. The results of the multifactorial analysis indicated that the risk of both outcomes decreased slightly during the period covered; was higher among patients with leg dermatitis; varied significantly with age and increased progressively with the number of additional positive reactions to other standard series allergens. Cross-reactivity to other, selectively tested, aminoglycoside antibiotics was substantial (kappa = 0.67; 95%CI: 0.63-0.71) for framycetin sulfate, to low (kappa = 0.33; 95%CI: 0.27-0.37) for gentamicin sulfate.

CONCLUSIONS

The prevalence of contact sensitization to neomycin sulfate was noteworthy among patients patch tested in the IVDK centers. Supplementing clinical epidemiology, neomycin contact allergy has been estimated to be relatively common even on the level of the unselected population (prevalence approx. 1%). Hence, the topical use of neomycin sulfate by patients should be carefully monitored, considering its potential to induce ACD, with emphasis on subgroups at risk.

[Pruritus in pregnancy. A frequent diagnostic and therapeutic challenge]

Pruritus is the leading dermatological symptom during pregnancy. Besides preexisting or acquired dermatoses, there are a number of pregnancy-specific dermatological diseases such as PEP (polymorphic eruption of pregnancy, previously named PUPPP), pemphigoid (herpes) gestationis, and pruritus gravidarum that are accompanied by severe itching and scratching. Because of potential effects on the fetus, the treatment of pruritus in pregnancy requires prudent consideration. The use of topical and systemic treatments depends on the underlying aetiology of pruritus and the stage and status of the skin. In general, emollients, topical anti-pruritics and topical corticosteroids appear to be the safest options for localised forms of pruritus in pregnancy whereas systemic treatments and/or UV phototherapy are adequate for generalized pruritus. Systemic corticosteroids and a restricted number of antihistamines may be administered in severe cases. This paper highlights the major aetiologies of pruritus during pregnancy and points out the cornerstones of antipruritic therapy in recognition of our own clinical experiences and the current literature.

A high prevalence of sensitization still persists in leg ulcer patients: a retrospective series of 106 patients tested between 2001 and 2002 and a meta-analysis of 1975-2003 data

BACKGROUND

Sensitization to topical treatments used in leg ulcers is common. Questioning and patch testing are used to identify causative drugs or dressings.

OBJECTIVES

To study the current frequency of sensitization in our centre, to analyse previously published studies, and to compare sensitization in recent years with studies published before 1990.

METHODS

A retrospective study was undertaken of all patients admitted with leg ulcers in 2001 and 2002. Of the files of 235 patients with leg ulcers reviewed, we identified 106 patients (group A) who had been patch tested in our institution between 2001 and 2002 with the European standard series and an additional series. The frequency of sensitization was compared with an earlier unpublished retrospective study in our centre of 36 leg ulcer patients tested in 1988 (group B), with a group of unselected contact dermatitis patients tested between 1 January 1997 and 31 December 2000 in our centre (group C), and with results published in the literature. We performed a computerized database search of MEDLINE and compared results obtained in recent years with those obtained before 1990 to obtain evidence of changing trends.

RESULTS

Seventy-five per cent of the 106 patients had at least one positive reaction, and 57% had two or more positive reactions. Balsam of Peru was positive in 40% of cases, followed by lanolin (21%), fragrance mix (18%), trichlocarban (13%), colophony (11%), Cetavlon (cetrimide cream) (9%) and neomycin (9%). Thirty-five of the 36 group B patients had at least one positive reaction. Lanolin was the most frequent (31%), followed by balsam of Peru (22%), Cetavlon (19%), colophony (14%), terebenthene (14%), quinoline mix (11%) and benzocaine (8%). Two hundred and eighty-six of 526 patients of group C were positive in at least one test (54.4%). Three allergens gave a sensitization rate >10%: balsam of Peru (12.5%), fragrance mix (15.2%) and nickel sulphate (21.1%). Review of the literature and calculation of sensitization rates in a pool of 3043 patients extracted from 24 series, plus our own, showed persistence of high sensitization rates and a significant (8.5%) increase in sensitization between the two periods compared. There was a decrease in sensitivity to lanolin, constant sensitization to aminoglycosides, a slight increase in sensitivity to thiuram mix and glucocorticoids, and a marked increase in sensitivity to balsam of Peru in France. Newer topical treatments and dressings showed very low rates of sensitivity with the exception of hydrogels.

CONCLUSIONS

Despite warnings, sensitization to topical treatments for leg ulcers is still frequent and, moreover, continues to increase, some variations reflecting local nursing practices and variations in topical treatment available. Although a decrease in sensitization rate with lanolin has been observed throughout the world, no decrease in sensitization rate has been demonstrated with aminoglycosides, and sensitization to glucocorticoids, thiuram mix and new products (hydrogels) is now increasingly being reported.