P.M. Farr

A portable instrument for quantifying erythema induced by ultraviolet radiation

The design and performance of an instrument for quantifying ultraviolet‐induced cutaneous erythema are discussed. If the instrument is used to record an‘erythema index’ at a site on the skin before and after irradiation, the difference between those two readings is essentially related to an increase in vasodilation and is largely independent of the melanin content of the epidermis.

An update and guidance on narrowband ultraviolet B phototherapy: a British Photodermatology Group Workshop Report.

Summary These guidelines for use of narrowband (TL‐01) ultraviolet B have been prepared for dermatologists by the British Photodermatology Group on behalf of the British Association of Dermatologists. They present evidence‐based guidance for treatment of patients with a variety of dermatoses and photodermatoses, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of background photobiology.

Narrow-band ultraviolet B and broad-band ultraviolet A phototherapy in adult atopic eczema: a randomised controlled trial

BACKGROUND Narrow-band ultraviolet B (UVB) is an effective treatment for psoriasis, and open studies suggest that this phototherapy might improve atopic eczema. We did a randomised controlled trial to compare narrow-band UVB, UVA, and visible light phototherapy as second-line, adjunctive treatments in adult patients with moderate to severe atopic eczema. METHODS Phototherapy was administered twice a week for 12 weeks. 26 patients were randomly assigned narrow-band UVB, 24 were assigned UVA, and 23 visible fluorescent light. The primary endpoints were change in total disease activity (sum of scores at six body sites) and change in extent of disease after 24 treatments compared with baseline. Data were analysed by the method of summary measures. FINDINGS 13 patients withdrew or were excluded from analysis. Mean reductions in total disease activity over 24 treatments in patients who received narrow-band UVB and UVA, respectively, were 9.4 points (95% CI 3.6 to 15.2) and 4.4 points (-1.0 to 9.8) more than in patients who received visible light. Mean reductions in extent of disease after 24 treatments with narrow-band UVB and UVA were 6.7% (1.5 to 11.9) and -1.0% (-5.3 to 3.3) compared with visible light. A small proportion of patients developed erythema after phototherapy or had a flare in their eczema sufficient to withdraw from treatment. INTERPRETATION Narrow-band UVB is an effective adjunctive treatment for moderate to severe atopic eczema, and the treatment is well tolerated by most patients.

A randomized comparison of narrow-band TL-01 phototherapy and PUVA photochemotherapy for psoriasis

BACKGROUND Although PUVA treatment of psoriasis is more effective than conventional or broad-band UVB phototherapy, two small studies have suggested that narrow-band or TL-01 phototherapy may have a therapeutic effect equal to PUVA. If confirmed, this would be of considerable importance as TL-01 therapy is likely to be considerably safer in the long term than PUVA. OBJECTIVE The purpose of this study was to compare PUVA with narrow-band (TL-01) phototherapy in psoriasis. METHODS We studied 100 patients with plaque-type psoriasis who were randomly allocated to twice-weekly treatment with PUVA or narrow-band UVB. RESULTS Clearance of psoriasis was achieved in a significantly greater proportion of patients treated with PUVA (84%) than with TL-01 (63%) (P =.018), and with significantly fewer treatments (median number of treatments for clearance with PUVA, 16.7; with TL-01, 25.3; P =.001). Only 12% of those treated with TL-01 were clear of psoriasis 6 months after finishing treatment compared with 35% for PUVA (P =.002). CONCLUSION When given twice weekly, PUVA is more effective for psoriasis than narrow-band UVB phototherapy.

Quantitative studies on cutaneous erythema induced by ultraviolet radiation

A reflectance instrument was used to measure the variation in UVR‐induced erythema at different positions on the back. The pre‐irradiation erythema index decreased from top to bottom of the back but the increase in index remained constant for a fixed exposure dose. In contrast, the minimal erythema dose was higher at lower sites on the back. The measured erythemal response increased linearly with the logarithm of the radiation dose from approximately the minimal erythema dose up to at least fifteen times this value.

Guidelines for topical PUVA: a report of a workshop of the British Photodermatology Group

Psoralen photochemotherapy [psoralen ultraviolet A (PUVA)] plays an important part in dermatological therapeutics, being an effective and generally safe treatment for psoriasis and other dermatoses. In order to maintain optimal efficacy and safety, guidelines concerning best practice should be available to operators and supervisors. The British Photodermatology Group (BPG) have previously published recommendations on PUVA, including UVA dosimetry and calibration, patient pretreatment assessment, indications and contraindications, and the management of adverse reactions .1 While most current knowledge relates to oral PUVA, the use of topical PUVA regimens is also popular and presents a number of questions peculiar to this modality, including the choice of psoralen, formulation, method of application, optimal timing of treatment, UVA regimens and relative benefits or risks as compared with oral PUVA. Bath PUVA, i.e. generalized immersion, is the most frequently used modality of topical treatment, practised by about 100 centres in the U.K., while other topical preparations tend to be used for localized diseases such as those affecting the hands and feet. This paper is the product of a recent workshop of the BPG and includes guidelines for bath, local immersion and other topical PUVA. These recommendations are based, where possible, on the results of controlled studies, or otherwise on the consensus view on current practice.

Calcipotriol improves the response of psoriasis to PUVA.

Summary Combining PUVA with other therapeutic agents which reduce the UVA dose required for clearance of psoriasis may be of benefit by reducing the long‐term risk of cutaneous malignancy and by increasing the efficacy of treatment. We have therefore studied the effect of calcipotriol in 13 patients with plaque‐type psoriasis who were about to start twice weekly PUVA. In each patient, from the start of PUVA treatment, two plaques on symmetrical body sites were selected for assessment. Calcipotriol ointment was applied to one twice daily, and placebo to the other. Response was assessed weekly for 6 weeks: an investigator, unaware of treatment allocation. compared psoriasis severity within each of the plaques, and blood flux was measured using a scanning laser‐Doppler velocimeter. Of the 11 patients who completed the study, in nine the calcipotriol‐treated plaque either cleared before the placebo‐treated plaque (n=7) or was consistently judged to be better (n = 2). From the third week of the trial, mean blood flux was significantly lower in the calcipotriol‐treated plaques than in those treated with placebo. In the seven patients whose psoriasis was clear in at least one plaque at the end of the study period, there was a median reduction in UVA dose of 26·5% for calcipotriol compared with placebo. With the exception of one patient, the improved response was not associated with earlier relapse.

Photopatch testing of 1155 patients: results of the U.K. multicentre photopatch study group

Background  Photoallergic contact dermatitis can be difficult to diagnose if not appropriately investigated. Currently, the most common U.K. photoallergens appear to be sunscreen chemicals. The investigation of choice is photopatch testing (PPT), which is probably underused. In part, this is due to differences in methodology and results interpretation.

The erythemal response of human skin to ultraviolet radiation

A reflectance instrument was used to measure objectively the erythemal response of human skin to ultraviolet radiation. Dose‐response curves have been constructed for four radiation wavelengths. In each case, the measured increase in erythema was found to be linearly related to the logarithm of the dose of ultraviolet radiation. Significantly different slopes of response were obtained for radiation of 254 and 280 nm compared with 300 and 313 nm radiation. The relevance of these findings is discussed with relation to the mechanism of erythema production and the erythema action spectrum.

Skin cancers or premalignant lesions occur in half of high-dose PUVA patients

Although treatment of psoriasis with psoralen and ultraviolet A (PUVA) is associated with a long‐term risk of development of cutaneous squamous cell carcinoma (SCC), the role of PUVA alone is not established, as many patients in reported series had also received treatment with other carcinogens, such as superficial X‐rays or arsenic. We have recalled and examined 54 of the 63 patients still alive who have had PUVA treatment in our department, and who have been exposed to a cumulative UVA dose greater than 2000 J/cm2. None of the patients had been treated with superficial X‐rays or arsenicals.