Biopsy outperforms reflectance confocal microscopy in diagnosing and subtyping basal cell carcinoma: results and experiences from a randomized controlled multicentre trial

Background

Reflectance confocal microscopy (RCM) is a noninvasive method for skin assessment, allowing entire lesion evaluation up to the papillary dermis. RCM is a potentially attractive alternative to punch biopsy (PB) in basal cell carcinoma (BCC).

Objectives

To determine the diagnostic accuracy of RCM vs. PB in diagnosing and subtyping BCC, and to study patient satisfaction and preferences.

Methods

Patients with a clinically suspected primary BCC were randomized between RCM and biopsy. Conventional surgical excision or follow‐up were used as reference. Sensitivity and specificity for BCC diagnosis and subtyping were calculated for both methods. BCC subtype was stratified based on clinical relevance: aggressive (infiltrative/micronodular) vs. nonaggressive (superficial/nodular) histopathological subtype and superficial vs. nonsuperficial BCC. Data on patient satisfaction and preferences were collected using a questionnaire and a contingent valuation method.

Results

Sensitivity for BCC diagnosis was high and similar for both methods (RCM 99·0% vs. biopsy 99·0%; P = 1·0). Specificity for BCC diagnosis was lower for RCM (59·1% vs. 100·0%; P < 0·001). Sensitivity for aggressive BCC subtypes was lower for RCM (33·3% vs. 77·3%; P = 0·003). Sensitivity for nonsuperficial BCC was not significantly different (RCM 88·9% vs. biopsy 91·0%; P = 0·724). Patient satisfaction and preferences were good and highly comparable for both methods.

Conclusions

Biopsy outperforms RCM in diagnosing and subtyping clinically suspected primary BCC. This outcome does not support routine clinical implementation of RCM, as a replacement for PBs in this patient group.

What is already known about this topic?

Expert groups have demonstrated the potency of in vivo diagnosing and subtyping of basal cell carcinoma (BCC) using confocal imaging. However, the diagnostic accuracy and financial consequences remain unclear, especially regarding correct subtyping.

What does this study add?

Confocal imaging was tested on performance in a real‐world clinical setting, as an alternative to diagnostic punch biopsies (PBs). In this setting, we concluded that for clinically suspicious primary BCC in daily practice, a PB remains preferred above confocal imaging, as it provides a superior accuracy for diagnosing and subtyping.

Linked Comment: Patalay. Br J Dermatol 2021; 184:590.

Is a single day patient friendly methyl aminolevulinate photodynamic therapy illumination scheme for superficial basal cell carcinoma feasible? A randomized multicenter pilot trial

BACKGROUND

Topical methyl aminolevulinate photodynamic therapy (MAL-PDT) is highly effective for the treatment of superficial basal cell carcinoma (sBCC). Current European treatment protocol requires two hospital visits, which is costly and unpractical. The aim of this study was to evaluate the efficacy of fractionated MAL-PDT, using two light fractions at 3 and 4 h compared to illumination at 3 and 5 h after MAL-application.

METHODS

Thirty patients were randomized into two groups. The first group received illumination at 3 and 4 h (20 + 55 J/cm²) after MAL-application (3/4 group). In the other group, two light fractions were performed at 3 and 5 h (20 + 55 J/cm²) after MAL-application (3/5 group). The lesion response was evaluated at 3 and 12 months posttreatment.

RESULTS

In the 3/5 group, 70.0% showed a complete response (CR) at 3 months compared to 63.6% in the other group. At 12 months, 100% showed a CR in the 3/5 group compared to 80.0% in the other group. However, most failures/recurrences were eventually due to the presence of a more aggressive BCC subtype, mostly caused by sampling error of the primary punch biopsy.

CONCLUSION

Single day protocol for MAL-PDT for sBCC is feasible and this study shows promising results.

Improving the applicability of guidelines on nonmelanoma skin cancer in frail older adults: a multidisciplinary expert consensus and systematic review of current guidelines

BACKGROUND

Balancing treatment decisions in frail older adults with nonmelanoma skin cancer (NMSC) can be challenging. Clinical practice guidelines (CPGs) could provide assistance.

OBJECTIVES

To collect and prioritize items related to frail older adults with NMSC for integration into CPGs and to assess the current extent of this integration.

METHODS

Items were collected and prioritized by a multidisciplinary working group (29 members) using a modified Delphi procedure and a five-point Likert scale. To assess current integration of these items in CPGs, a systematic review was subsequently performed by two independent reviewers using five medical databases (PubMed, Embase, Cochrane Library, SUMsearch and Trip Database), websites of guideline developers/databases, and (inter)national dermatological societies.

RESULTS

Prioritization of a final 13-item list showed that 'limited life expectancy' (4·5 ± 0·9) and 'treatment goals other than cure' (4·4 ± 0·7) were most desired to be integrated into CPGs; both were included in six (46%) of the CPGs found (n = 13). Attention to 'tumour characteristics' and 'comorbidities' were included in CPGs most often (100% and 77%, respectively).

CONCLUSIONS

More attention to items related to frail older adults in NMSC CPGs is broadly desired, but CPG integration of these items is currently limited. More integration might stimulate more holistic, personalized and patient-centred care in frail older adults.

A four-phase strategy for the implementation of reflectance confocal microscopy in dermatology

BACKGROUND

Reflectance confocal microscopy (RCM) is gradually implemented in dermatology. Strategies for further implementation and practical 'hands on' guidelines are lacking.

OBJECTIVE

The primary outcome was to conduct a general strategy for further implementation of RCM. The secondary outcome was the diagnosis of psoriasis and differentiation of stable from unstable psoriatic plaques by means of the 'hands on' protocol, derived from the strategy.

METHODS

We used a four-phased model; an exploring phase, a systematic literature search, a clinical approach and, finally, an integration phase to develop a clinical guideline for RCM in psoriasis. Receiver operating characteristic curve statistics was applied to define the accuracy for the diagnosis of unstable psoriasis.

RESULTS

A general strategy for further implementation of RCM and practical approach was developed to examine psoriasis by RCM and to distinguish stable from unstable psoriasis. Unstable psoriasis was diagnosed by epidermal inflammatory cell counts with a sensitivity and specificity of 91.7% and 98.3%, respectively, and with an accuracy of 0.92 (area under the curve). In addition, a monitoring model was proposed.

CONCLUSION

This is the first study that shows a method for implementation of RCM in dermatology. The strategy and hands on protocol for psoriasis may serve as a model for other dermatological entities and additionally may lead to specialized ready-to-use RCM protocols for clinical dermatological practice.

Pain identifies squamous cell carcinoma in organ transplant recipients: the SCOPE-ITSCC PAIN study

Organ transplant recipients (OTR) are at high risk for cutaneous squamous cell carcinomas (SCC). We aimed to define clinically meaningful patient-reported warning signals predicting the presence of invasive SCC.Patient-reported signs and symptoms of 812 consecutively biopsied skin lesions from 410 OTR were determined by questionnaire and physical examination and related to the subsequent biopsy-proven diagnoses. Receiver-operating characteristic (ROC) curve analyses were used as a measure of distinction between the predictive values of patient-reported warning signals and the occurrence of SCC. Pain was an independent predictive patient-reported warning signal for a biopsy-proven invasive SCC. The odds ratio from the fully adjusted model predicting SCC was 4.4(95% confidence interval: 2.4–8.2). Higher scores on the visual analog scale (VAS) for pain were associated witha greater likelihood for the presence of SCC compared to none or mild pain. The for scores on the VAS from 1to 3, 4 to 6 and 7 to 10 were 4.9 (2.2–10.5), 2.3 (0.96–5.5)and 16.5 (3.6–75.8), respectively. Pain is the most powerful patient-reported warning signal for invasive cutaneous SCC in OTR. Empowerment of patients by education could accelerate diagnosis and treatment of cutaneous SCC.

Photodynamic therapy for skin field cancerization: an international consensus. International Society for Photodynamic Therapy in Dermatology

Field cancerization is a term that describes the presence of genetic abnormalities in a tissue chronically exposed to a carcinogen. These abnormalities are responsible for the presence of multilocular clinical and sub-clinical cancerous lesions that explains the increased risks of multiple cancers in this area. With respect to the skin, this term is used to define the presence of multiple non-melanoma skin cancer, its precursors, actinic keratoses and dysplastic keratinocytes in sun exposed areas. The multiplicity of the lesions and the extent of the area influence the treatment decision. Providing at least equivalent efficacy and tolerability, field directed therapies are therefore often more worthwhile than lesion targeted approaches. Photodynamic therapy (PDT) with its selective sensitization and destruction of diseased tissue is one ideal form of therapy for this indication. In the following paper the use of PDT for the treatment of field cancerized skin is reviewed and recommendations are given for its use.

Photodynamic therapy for actinic keratosis in organ transplant patients

BACKGROUND

The incidence of actinic keratoses (AK) and non-melanoma skin cancer (NMSC) in organ transplant recipients (OTRs) is significantly higher than in immunocompetent patients. Rates of progression and recurrence following treatment are higher too, in part due to the effects of the immunosuppressant drugs. Conventional therapies for AK, using curettage, cryotherapy, surgical excision, topical therapies and photodynamic therapy (PDT), are often less effective, and may be inappropriate, for treating the greater numbers and extent of lesions in OTRs. Moreover, there are no specific protocols for treating this patient population that take into account the need for more frequent treatment and the increased pain associated with treating larger areas.

OBJECTIVES

Recently, a pan-European group of dermatologists with expertise in this area met to share current best practice in PDT for the treatment of AK in OTRs.

METHODS

The group identified areas where PDT currently is not meeting the needs of these patients and discussed how these gaps might be addressed.

RESULTS/CONCLUSIONS

This position article summarizes those discussions and makes recommendations concerning a standardized protocol for treating OTRs, for a large randomized controlled trial to provide robust data on safety, efficacy and optimal pain control, and to provide pharmaco-economics data that can be used to support extended reimbursement in this patient group. The authors also recommend a second clinical trial to further investigate induced immunosuppression with PDT in healthy volunteers.

Pretreatment to enhance protoporphyrin IX accumulation in photodynamic therapy

The response rates of photodynamic therapy (PDT) vary widely. Limited uptake of topically applied 5-aminolaevulinic acid (ALA), or its methyl ester (MAL), and suboptimal production of protoporphyrin IX (PpIX) may account for these differences. Recently, we demonstrated that hyperkeratosis is an important negative factor in ALA uptake. This review has its focus on pretreatment of the skin in order to improve the clinical outcome of ALA/MAL PDT. Pretreatment of hyperkeratosis can be achieved with keratolytics, curettage/debulking, tape stripping, microdermabrasion or laser ablation. Penetration enhancers may alter the composition or organization of the intercellular lipids of the stratum corneum. Several studies have been performed on the use of dimethyl sulfoxide, azone, glycolic acid, oleic acid and iontophoresis to increase the penetration of ALA. As PpIX production is also dominated by temperature-dependent processes, elevating skin temperature during ALA application may also improve treatment results. Another approach is the use of additives that interact with the heme biosynthetic pathway, e.g. by removing ferrous iron with iron-chelating substances such as: ethylenediaminetetraacetic acid; 3-hydroxypyridin-4-ones; 1,2-diethyl-3-hydroxypyridin-4-one-hydrochloride; and desferrioxamine. In conclusion, simple pretreatments or additions to the regular practice of PDT, aimed to optimize intralesional PpIX content, improve the clinical outcome.

[Regional metastases of head and neck cutaneous squamous cell carcinoma]

Two patients, a woman aged 54 years and a man aged 76 years, developed regional metastases of head and neck cutaneous squamous cell carcinoma (HNCSCC). In general, cutaneous SCC has a low metastatic potential. However these patients illustrate that this tumour may behave aggressively, metastasising to the regional lymph nodes in the neck or parotid gland. Certain clinical and histological features of the primary tumour are associated with a higher risk for nodal metastases. In patients at risk, a more rigorous investigation for nodal metastasis is warranted at diagnosis of SCC as well as during follow-up. The extent of treatment of lymph nodes in the neck region should be directed by the location of the primary tumour, which is an indicator of the most probable lymph drainage pattern. In the case of metastatic parotid involvement, elective treatment of the neck should be considered, even when there are no clinical signs of metastasis. Treatment consists of surgery and/or ipsilateral radiotherapy.

The Impact of Chronic Skin Disease on Daily Life (ISDL): a generic and dermatology-specific health instrument

BACKGROUND

In dermatological research and clinical practice, there is a need for comprehensive self-report instruments that assess a broad spectrum of health implications of chronic skin diseases, including generic and skin-specific aspects of disease-related quality of life. The advantages of dermatology-specific, multidimensional instruments over generic instruments or single-dimensional quality-of-life measures are in the detailed and specific information they provide about health areas that are affected by the skin condition and that may change through therapeutic intervention.

OBJECTIVES

The development of a multidimensional health status inventory for chronic skin diseases (Impact of Chronic Skin Disease on Daily Life, ISDL) is described. The dermatology-specific part of the inventory assesses dimensions of physical functioning, more specifically skin status, physical symptoms of itch, pain and fatigue and scratching responses as well as disease-related stressors like stigmatization. The generic part gauges dimensions of psychological functioning, disease-related impact, illness cognitions and social support by means of existing scales validated for other chronic diseases.

METHODS

Reliability and validity of the questionnaire were studied in various samples of patients with psoriasis and atopic dermatitis.

RESULTS

The ISDL showed high reliability and test-retest reliability in both patient groups. Convergent validity was indicated by moderate to strong correlations with other validated questionnaires. The scales proved sensitive to change both for dermatological ultraviolet B radiation therapy and cognitive behavioural treatment for itching.

CONCLUSION

With its convincing results for reliability and validity the present evaluation supports the usefulness and applicability of the instrument for different chronic skin diseases.

Dermatologists’ Adherence to the Guideline of the Dutch Society of Dermatology and Venereology with Respect to the Treatment with Methotrexate for Severe Chronic Plaque Psoriasis: Results from a Dutch Survey

BACKGROUND

In 2003, the Dutch guideline 'Photo(chemo) therapy and systemic therapy for severe chronic plaque psoriasis' was established.

OBJECTIVES

To document how closely this guideline is followed in clinical practice with respect to the methotrexate (MTX) treatment and to formulate recommendations to adjust the guideline.

METHODS

A survey was conducted among Dutch dermatologists and residents in dermatology. The questionnaire assessed the knowledge of and the adherence to the guideline with respect to MTX treatment.

RESULTS

Fifty percent of the contacted dermatologists/residents responded. Fifty-two percent follow the guideline with respect to MTX. Liver biopsy and the frequency of blood investigations cause a discrepancy between guideline and reality. There is a lack of consensus between guidelines of the different specialisms concerning liver biopsy.

CONCLUSION

The need for liver biopsies in combination with the frequent check-ups and the lack of consensus between rheumatologists, hepatologists and dermatologists seem to restrict the adherence to the guideline.

Heterogeneity of fluorescence in psoriasis after application of 5-aminolaevulinic acid: an immunohistochemical study

BACKGROUND

Psoriasis has been shown to highly accumulate protoporphyrin IX (PpIX), but a variable distribution within plaques after fluorescence diagnosis is seen. It is unknown what causes this heterogeneity of fluorescence in psoriatic skin, despite adequate keratolytic treatment. Variations in fluorescence might explain the variable and the mostly partial clinical response of psoriasis seen after photodynamic therapy (PDT).

OBJECTIVES

This study examines morphological and immunohistochemical differences in inhomogeneous PpIX-induced fluorescence in stable plaque psoriasis.

MATERIALS AND METHODS

Fourteen patients with stable plaque psoriasis were included in this study. In each patient one psoriatic plaque was incubated with 20% 5-aminolaevulinic acid (ALA) ointment for 3 h after keratolytic treatment. Fluorescence diagnosis with ALA-induced porphyrins (FDAP) was performed and subsequently high- and low-fluorescent psoriatic skin samples were biopsied. Biopsies were investigated with respect to histological hyperkeratosis (thickness of stratum corneum), proliferation (Ki-67 antigen), keratinization (K10, filaggrin) and inflammation (CD3). Digital images acquired with FDAP were analysed using image analysis software.

RESULTS

Inhomogeneous fluorescence was seen in 12 of the 14 plaques. A significantly thicker stratum corneum was found in low-fluorescent psoriatic skin compared with highly fluorescent skin. Fluorescence intensity and thickness of the stratum corneum proved to be negatively correlated. The variable-fluorescent parts of the lesional psoriatic skin showed no differences in epidermal proliferation, keratinization or inflammation.

CONCLUSIONS

Heterogeneous ALA-induced fluorescence in psoriasis plaques related to inhomogeneous distribution of PpIX in the epidermis may result from differences in penetration of ALA and/or light within a plaque caused by differences in stratum corneum thickness. The variable clinical response seen after PDT in psoriasis could be explained by this. These findings are consistent with the general assumption that optimal desquamation prior to FDAP or PDT is required for the most favourable results.

Primary Cutaneous Marginal Zone B-Cell Lymphoma

BACKGROUND

Primary cutaneous marginal zone B-cell lymphoma (PCMZL) is a low-grade B-cell lymphoma that originates in the skin, with no evidence of extracutaneous disease. Studies focusing on the optimal treatment of PCMZL have not been published thus far. We describe 50 patients with PCMZL to further characterize clinical characteristics and outcome and, in particular, to evaluate our current therapeutic approach.

OBSERVATIONS

The majority of the patients (36/50 [72%]) presented with multifocal skin lesions, and 14 patients (28%) presented with solitary or localized lesions. The initial treatment of patients with solitary lesions consisted of radiotherapy or excision, whereas patients with multifocal lesions received a variety of initial treatments, most commonly radiotherapy and chlorambucil therapy. Cutaneous relapses developed in 19 (48%) of 40 patients who had complete remission and were more common in patients with multifocal disease. After a median period of follow-up of 36 months, 2 patients developed extracutaneous disease, but none of the patients died of lymphoma.

CONCLUSIONS

Patients with PCMZL who have solitary lesions can be treated effectively with radiotherapy or excision. For patients with PCMZL who have multifocal lesions, chlorambucil therapy and radiotherapy are suitable therapeutic options. In case of cutaneous relapses, the beneficial effects of treatment should carefully be weighed against the potential adverse effects.

Quality of life in vitiligo patients after treatment with long-term narrowband ultraviolet B phototherapy

Long-term treatments for chronic diseases such as vitiligo need to be evaluated for their clinical efficacy. Assessment of the quality of life (QOL), however, may provide the most relevant information on the actual benefit for these patients. In this study we evaluated QOL after long-term narrowband ultraviolet (UV) B for the treatment of vitiligo. All patients, with long-term stable vitiligo vulgaris, who were treated at our clinic during the last 4 years received specifically for this study a designed QOL questionnaire, which included questions about general well-being, camouflage and psychosocial aspects; 71.4% of the patients responded. Most patients indicated an improvement on a psychological level, but an increase in camouflaging. The present study shows that, after long-term narrowband UVB phototherapy, skin appearance does not play a major role in the life of vitiligo patients, while well being only improved in a minority of patients.

The differential effect of broad band vs narrow band UVB with respect to photodamage and cutaneous inflammation

Since Fischer reported on the superiority of 313 nm UVB compared with broad band UVB in the treatment of psoriasis, narrow band UVB has become the main phototherapeutical modality in several countries. There is some discussion about the safety and photobiological effects of narrow band UVB. In the present study, narrow and broad band UVB have been compared with respect to parameters for photodamage and inflammation. Fourteen healthy volunteers were randomized in two groups. Both groups were irradiated with three minimal erythema doses (MED) of narrow or broad brand UVB, respectively. Before and 4, 24 and 48 h after irradiation, 6 mm biopsies were taken from immunohistochemical analysis of p53, apoptosis and p16 (photodamage parameters) and T-cells, polymorphonuclear leukocytes (PMN) and Langerhans' cells (inflammatory cells). Mean MED for narrow band UVB was 8.125 times higher than broad band UVB. Significant changes in expression were seen for all parameters except for p16. P53, apoptosis, T-cells and PMN increased, while Langerhans' cell count decreased significantly. No significant differences were seen between the narrow band UVB. In conclusion, following irradiation of three MED narrow band UVB and broad band UVB safety parameters for carcinogenesis and inflammation were induced to the same extent. As narrow band UVB is more effective than broad band UVB, the present study suggests superiority of narrow band UVB as a treatment with a better benefit risk ration.

Effectiveness and side effects of UVB-phototherapy, dithranol inpatient therapy and a care instruction programme of short contact dithranol in moderate to severe psoriasis

The efficacy of UVB-phototherapy (UVB) and dithranol treatment for psoriasis is well established. However, well-conducted clinical trials on the efficacy of dithranol are not available, making comparison between these time-honoured treatments with currently available therapies impossible. We studied the effectiveness of dithranol in a care instruction programme using short time exposures (short contact treatment), UVB-phototherapy and dithranol treatment in an inpatient setting. In an open randomised study we included 250 patients with moderate to severe psoriasis. The intention to treat group existed of 238 patients. 100 patients were treated with short contact dithranol, 78 Patients were treated with UVB and 60 patients underwent inpatient dithranol treatment. We found UVB and dithranol treatment to be effective and safe in moderate to severe psoriasis. The efficacy of short contact dithranol treatment equals the efficacy of UVB-phototherapy. Dithranol treatment at the inpatient department showed superior efficacy in clinical response rate and treatment duration as compared to UVB and short contact treatment. The median number of days in remission was significantly longer after short contact treatment as compared to inpatient treatment. Although the use of dithranol is hampered by skin irritation and staining, the present study shows that dithranol treatment has an outstanding efficacy and safety profile. Comparison between different antipsoriatic treatments should, besides clearing capacity, reconcile duration of remission, safety, patient acceptability and costs.

Adalimumab, a fully human anti-TNF-alpha monoclonal antibody, treatment does not influence experimental UV response in the skin of rheumatoid arthritis patients

TNF-alpha is known to play an important role in UV-induced immunomodulation and photodamage. It plays a role in UVB-mediated induction of apoptosis and is a strong inducer of the c-Jun N-terminal kinase (JNK) pathway, which eventually leads to the loss of dermal collagen and elastin content. Recently chimeric anti-TNF-alpha has been introduced as a therapy for rheumatoid arthritis. The aim of the present study was to investigate the effect of anti-TNF-alpha treatment on UV-induced DNA damage, apoptosis, and induction of matrix metallo proteinases. Twelve patients with rheumatoid arthritis were included and irradiated with 2 MED broadband UVB before and after administration of 0.5 mg/kg anti-TNF-alpha monoclonal antibody. Twenty-four hours after irradiation biopsies were taken. Frozen and paraffin sections were stained for p53, c-Jun, phosphorylated c-Jun, sunburn cells and MMP-1. No significant changes were observed in the expression of p53 and sunburn cells and MMP-1 content after treatment with anti-TNF-alpha, whereas a slight but significant decrease in c-Jun and phosphorylated c-Jun expression was noted (P = 0.0250 and P = 0.0431, respectively). Our results showed no influence of anti-TNF-alpha on UV response at therapeutic doses in patients with rheumatoid arthritis.

Treatment of vitiligo vulgaris with narrow band UVB (311 nm) for one year and the effect of addition of folic acid and vitamin B12

Narrow band UVB is succeeding psoralen and UVA irradiation as the main treatment of vitiligo vulgaris in several European countries. Vitamin B12 and folic acid deficiency in some vitiligo patients has prompted researchers to investigate the efficacy of these vitamins in the treatment of vitiligo. In the present controlled study we investigated the value of narrow band UVB phototherapy in the treatment of vitiligo and the possible additive effect of vitamin B12 and folic acid. Twenty-seven patients with long-term stable vitiligo were included and randomized in a "UVB only" (UVB) or "UVB combined with vitamin B12 and folic acid" (UVB+) group. Patients were irradiated thrice weekly for one year, whilst repigmentation was carefully monitored. In 92% (25/27) of the patients up to 100% repigmentation was seen. Repigmentation was notable in lesions on the face, neck and throat, lower arm, chest, back and lower legs, whilst repigmentation on the hands, wrists, feet and ankles proved to be minimal. Maximum repigmentation rates did not differ significantly between the UVB group and the UVB+ group. Our study reconfirms that narrow band UVB phototherapy is an effective treatment for vitiligo and shows that co-treatment with vitamin B12 and folic acid does not improve the outcome of treatment of vitiligo with narrow band UVB phototherapy.

The effects of topical corticosteroids and a coal tar preparation on dithranol-induced irritation in patients with psoriasis

Dithranol has been a mainstay in the treatment of psoriasis for more than 80 years. Although a safe approach, the irritation of the clinically uninvolved perilesional skin remains a major limitation of this treatment. Corticosteroids and coal tar solution have an anti-inflammatory potential. The aim of the present study was to investigate the clinical and cell-biological effects of two topical corticosteroids and a coal tar preparation on dithranol-irritated skin. During 4 consecutive days, 2% dithranol cream was applied to six uninvolved skin sites (3 cm in diameter) on the lower back of 9 patients with psoriasis. Dithranol was left on the skin for 1 h, subsequently removed with water and soap and the skin was dried with a towel. Subsequently, SITE 1 was treated with 0.05% clobetasol-17-propionate ointment (CP), SITE 2 with unguentum cetomacrogolis (vehicle 1), SITE 3 with 0.005% fluticasonpropionate ointment (FP), SITE 4 with 10% coal tar solution in lanettewax cream (CTS), SITE 5 was left untreated (control) and SITE 6 was treated with lanettewax cream (vehicle 2). Erythema, oedema and vesicle formation was scored every day. On day 5, punch biopsies were taken from the six sites. The expression of epidermal proliferation, differentiation and inflammation markers and the clinical irritation scores indicate that the application of a high potency corticosteroid (CP) is the best approach to minimise dithranol irritation, whereas CTS had virtually no effect on dithranol irritation during this 4-day experimental model.

An immunohistochemical assessment of the response of the psoriatic lesion to single and repeated applications of high-dose dithranol cream

Dithranol, although a time-honoured treatment and from the beginning of the previous century still going strong, remains an empirical treatment. There is growing evidence that the biochemical basis for the mechanism of action of dithranol at the molecular level is related to the redox activity leading to the production of active oxygen species, which include singlet oxygen, superoxide anion radical and hydroxyl radical. Some authors suggest that epidermal proliferation and/or keratinisation may be the target for dithranol, while others refer to aspects of cutaneous inflammation as crucial in the antipsoriatic effect of dithranol. The present study aims to analyse the effect of single and repeated applications of dithranol on aspects of epidermal proliferation, keratinisation and inflammation in the psoriatic plaque. The most marked effect of dithranol proved to be that on epidermal proliferation (the number of Ki-67-positive nuclei) with an early reduction already 1 day following the single application. This reduction lasted for 16 days. However, such an application induced only a modest clinical improvement. Repeated challenges, resulting in a decrease in the number of Ki-67-positive nuclei of 66%, led to a substantial clinical improvement after 12 days. Repeated challenges resulted in a significant reduction of the number of polymorphonuclear leucocytes. However, this reduction was less pronounced as compared to the effect on epidermal proliferation. It is concluded that epidermal proliferation is a sensitive marker to demonstrate an early effect of dithranol. The dynamics of the cell-biological responses suggest that intermittent applications might be a promising new approach. As dithranol does not reduce the number of T lymphocytes, it is attractive to speculate that the combination of dithranol with immunosuppressive treatments might be a very effective combination.

The response of uninvolved skin of patients with psoriasis to single and repeated applications of dithranol cream: an immunohistochemical assessment

Dithranol is one of the most effective topical treatments for patients with psoriasis. The well-known irritation is a serious limitation. In an earlier study we investigated the inflammatory response to single and repeated applications with dithranol 2% cream in skin from healthy volunteers. In the present study, we assessed the clinical and cell-biological response of single and repeated challenges with dithranol 2% cream in uninvolved skin of patients with psoriasis. A striking difference between the two studies is the late phase in the single-challenge group after 8 days, showing a longer-lasting response in the uninvolved skin compared to normal skin with respect to proliferation and inflammation markers. A controlled and synchronised irritation by dithranol might induce anti-inflammatory processes and as such constitute an antipsoriatic principle. It is attractive to speculate that in psoriasis the induction of anti-inflammatory responses is defective. Following repeated applications of dithranol, a more uniform course of proliferation, differentiation and inflammation markers was observed in the uninvolved psoriatic skin as compared to the skin of healthy volunteers. Again a defect in the induction of anti-inflammatory responses might account for this event. In view of these differences between normal skin and psoriatic uninvolved skin, it may be advisable to use the uninvolved skin of patients with psoriasis in further studies on the interference between dithranol irritancy and various anti-inflammatory agents.

The response of normal human skin to single and repeated applications of dithranol cream: an immunohistochemical assessment

The irritative response of uninvolved skin is a serious limitation of dithranol therapy in psoriasis. A characterisation in cell biological terms may be helpful in finding an effective counteraction to this well-known irritation. Therefore, we studied the effect of single and repeated applications of dithranol on normal human skin. Besides a clinical evaluation, we studied aspects of epidermal proliferation, differentiation and inflammation. On day 2, after single dithranol challenge, we observed an induction of both the cornified envelope precursor protein involucrin and the cross-linking enzyme transglutaminase I. Subsequently, epidermal hyperproliferation was observed with a maximum on day 8. The epidermal response to dithranol appears to be a reinforcement of the barrier function. Remarkably, however, filaggrin was found to be decreased. Profilaggrin breakdown might be an attempt to compensate for xerosis of uninvolved skin that accompanies dithranol therapy. T lymphocytes and to a lesser extent polymorphonucleocytes were found to be significantly increased. The reduction of Langerhans cells suggests a dose-dependent toxic effect of dithranol or one of its metabolites on Langerhans cells. The dynamics in the induction of changes after repeated challenge are comparable with those after single challenge. However, the induction of hyperproliferation following repeated application appeared to continue between day 8 and 12. Based on the dynamics of dithranol-induced irritation, it may be of interest to study the efficacy of intermittent dithranol treatment. Our results indicate that an optimal timing for biopsies in future dithranol irritation studies lies between 4 and 8 days after the first dithranol challenge.

Combining lesional short-contact dithranol therapy of psoriasis with a potent topical corticosteroid

BACKGROUND

Since its introduction, the effectiveness of dithranol in treating psoriasis has been unequalled by other topical treatments. Out-patient short-contact dithranol treatment is effective with regard to clinical response rate and relapse rate after 1 year. A drawback, however, is the relatively long treatment duration.

OBJECTIVES

To study a dithranol regimen combined with a potent topical corticosteroid with regard to clinical response rate, treatment duration and remission period after clearance.

METHODS

Twelve patients with stable psoriasis vulgaris participated in this study. We treated three comparable psoriasis lesions on the extremities for 39 consecutive days. The first lesion was treated daily with short-contact dithranol cream followed by clobetasol-17-propionate ointment 5 days per week. The second lesion was treated daily with short-contact dithranol cream followed by the vehicle of clobetasol-17-propionate ointment. The third lesion was treated with clobetasol-17-propionate ointment 5 days per week. The patients attended on days 1, 4, 9, 12, 15, 18, 22, 25, 32 and 39 during treatment. We assessed lesional severity scores at each visit and registered the baseline area at the first visit. During the follow up at weeks 2, 4, 6, 10, 14, 19 and 23 we assessed lesional sum scores. We also estimated the area involved in recurrence of the lesion as a percentage of the baseline area. The overall differences between the three treatment curves for the treatment period and follow-up period separately were tested with a likelihood ratio test.

RESULTS

Differences between the curves of the sum scores during treatment (P < 0.001) were mainly due to the different time-course of dithranol monotherapy, which showed a slower decrease in sum score. Differences between the linear trends of the sum score (P < 0.001) and the area score P < 0.001) during follow up were due to a different time-course of the combination therapy, which started lower and increased more slowly, suggesting a slower relapse rate with combination therapy. When comparing the follow-up data, it must be kept in mind that the three treatments showed an overall significantly different sum and area score at the start of follow up.

CONCLUSIONS

Intermittent addition of clobetasol-17-propionate ointment enhanced the antipsoriatic efficacy of short-contact, high-dose dithranol therapy in terms of clearing capacity and treatment duration, without shortening remission duration.