A new approach to actinic folliculitis: prophylactic narrowband ultraviolet B phototherapy.

BACKGROUND: We have observed an increasing number of patients referred to the Scottish Photobiology Service (SPS), who were later diagnosed with actinic folliculitis (AF) and had positive phototesting results. Treatment options for AF are limited, with only a few reports in the literature. The use of prophylactic narrowband ultraviolet B (NB-UVB) phototherapy for AF has not previously been described, and we report on this for the first time. AIM: To analyse the clinical characteristics, phototesting results and responses to treatment for patients with AF diagnosed by the SPS. METHODS: We undertook a retrospective review over 10 years of all case notes of patients who were assessed and diagnosed with AF through the SPS, based at the Photobiology Unit, Dundee, UK. RESULTS: All 10 patients were women. Mean age of onset was 25 years and mean time to referral for investigation was 7 years. The commonest site involved was the face, with the main clinical feature being monomorphic pustules appearing after sunlight exposure. The eruption could be provoked with iterative doses of broadband UVA irradiation in five patients. All patients were offered photoprotective advice and prophylactic NB-UVB phototherapy. Five patients proceeded with phototherapy; four of these completed the desensitization course and all four reported either a delay in symptom onset or total prevention of rash induction, with complete efficacy of desensitization maintained for 3 years in one patient. CONCLUSION: We demonstrate the successful use of UVA provocation testing as a diagnostic tool in AF. Additionally, we recommend the use of prophylactic NB-UVB phototherapy in AF as an effective and well-tolerated approach.

Frequency of occurrence of polymorphic light eruption in patients treated with photohardening and patients treated with phototherapy for other diseases.

BACKGROUND: Medical phototherapy can lead to the manifestation of polymorphic light eruption (PLE), though little is known about the frequency of such events. AIMS: The aim of this Austrian single center study was to retrospectively investigate over a 4-year time period the frequency of PLE in patients prone to the condition and patients with other diseases under phototherapy (mainly narrow-band and broad-band UVB). MATERIALS AND METHODS: The data for analysis were obtained from the electronic health and patient record database and patient files of the Photodermatology Unit, Department of Dermatology, Medical University of Graz, Austria. RESULTS: PLE occurred in 24.3% (18/74) of PLE patients but only 0.7% (3/421) of psoriasis patients under phototherapy (chi-square; P < 0.0001). PLE also occurred in 1.2% (3/257) of patients with atopic eczema, 0.8% (1/118) with prurigo, 3.5% (4/115, P = 0.0206) with parapsoriasis en plaques/mycosis fungoides, 7.4% (2/27, P = 0.0013) with granuloma anulare, 14.3% (1/7, P = 0.0002) with scleroderma, and 16.7% (1/6, P < 0.0001 vs. psoriasis) with pityriasis lichenoides chronica or pityriasis lichenoides eruptiva et varioliformis acuta. DISCUSSION AND CONCLUSION: These results are helpful for treatment allocation and risk estimation of PLE occurrence with regard to obtaining informed consent not only from PLE-prone patients but also from patients with other skin disorders commonly treated by phototherapy.

Induction of Light Tolerance Using Narrowband UV-B in Solar Urticaria. / Inducción de fototolerancia con ultravioleta B de banda estrecha en urticaria solar.

INTRODUCTION: Solar urticaria is an uncommon photodermatosis. First-line treatment is with antihistamines; second-line treatment includes induction of light tolerance using UV phototherapy. OBJECTIVES: We aimed to describe and evaluate the effectiveness of a desensitization protocol with narrowband UV-B in patients with solar urticaria. MATERIAL AND METHODS: We performed a retrospective study of patients with solar urticaria with an action spectrum in the UV-A range, the visible light range, or both who had received therapy with narrowband UV-B for induction of light tolerance. Short courses of treatment were administered (<20 sessions, 3 per week) during spring. The initial dose was determined according to the skin type. The Skindex-29 was administered before treatment and after summer; a nonvalidated questionnaire was also administered after summer to evaluate disease activity and satisfaction with treatment. RESULTS: We included 8 patients with an action spectrum (4 with visible light and 4 with UVA plus visible light). Seventeen courses (1-6 per patient) were administered per year. The number of sessions per year ranged from 11 to 20. The mean dose of narrowband UV-B per course was 7.45J/cm2. No patients experienced flares or adverse effects during treatment. The response was satisfactory in 6 patients. The improvement in the overall Skindex-29 score was greater than 20% in 78.6% of cases. The improvement in the function and symptoms subscales was over 20% in 71% and 64% of cases, respectively. CONCLUSION: Induction of light tolerance with narrowband UV-B in solar urticaria is safe and effective in a high percentage of patients.

Evaluation of narrow band ultraviolet B phototherapy in the treatment of chronic actinic dermatitis in Chinese patients.

Few studies have been conducted in chronic actinic dermatitis (CAD) treated with narrowband ultraviolet B (NB UVB) phototherapy, especially in Asian patients. We aim to evaluate the efficacy and safety of NB UVB phototherapy in Chinese patients with CAD. 19 CAD patients of Fitzpatrick skin phototype IV received NB UVB phototherapy in spring and treatments were given 3 times weekly with incremental dose and maintenance therapy was given twice weekly for 3-4 weeks. The mean initial, endpoint, and cumulative dose of NB UVB was 0.08, 0.33, and 6.0 J/cm2 , respectively. Patients totally received 27 times of treatments in average. 87.5% of previously ultraviolet B（UVB） sensitive patients and 75% of previously ultraviolet A（UVA） sensitive patients had normal or improved MED after phototherapy. The percentage of patients returned to normal UVB phototesting was higher than that of patients returned to normal UVA phototesting (68.8% vs. 37.5%). The mean 1-week DLQI and the need for using immunosuppressive agents and antihistamines were significantly reduced after treatment (p < .01 or p < .05). In conclusion, prophylactic NB UVB phototherapy is effective and safe in treatment of CAD in Chinese patients with Fitzpatrick skin phototype IV.

Successful Short Desensitization Treatment Protocol with Narrowband UVB Phototherapy (TL-01) in Polymorphic Light Eruption.

INTRODUCTION: Polymorphic light eruption (PLE) is a common idiopathic photodermatosis that typically presents with pruritic papular or papulovesicular lesions on sun-exposed skin between spring and autumn. In many subjects PLE is mild, and can usually be prevented by the use of broad-spectrum topical sunscreens and a gradual increase in sunlight exposure. However, in some individuals, sunlight exposure results in florid PLE and they often benefit from prophylactic desensitization treatment using phototherapy in early spring, an artificial method that induces a "hardening" phenomenon. OBJECTIVE: To describe and evaluate the efficacy of a short desensitization protocol, based on a one-month-treatment, administered twice a week with narrow band UVB in subjects with severe polymorphic light eruption (PLE). METHODS: A retrospective, open planned and non-randomized study to assess the efficacy of UVB phototherapy in prevention of polymorphic light eruption. RESULTS: Fifteen subjects diagnosed with severe PLE were treated with the standard protocol in our Photobiology Unit between 2014 and 2015. The effect of hardening was sustained during follow up in 87.5% of desensitization treatments. A statistically significant association (p<0.05) between the years of duration of the PLE and the response to treatment was found. CONCLUSIONS: The effect of hardening was maintained in the vast majority of subjects, obtaining a good benefit with no PLE episodes during all the summer. We demonstrate that our standard protocol is effective, and produces a successful outcome for the majority of PLE subjects. Our protocol is shorter than those currently applied, being favourable both for the patient and the physician.

Levels and function of regulatory T cells in patients with polymorphic light eruption: relation to photohardening.

BACKGROUND: We hypothesized that regulatory T cells (Tregs) are involved in the immunological abnormalities seen in patients with polymorphic light eruption (PLE). OBJECTIVES: To investigate the number and suppressive function of peripheral Tregs in patients with PLE compared with healthy controls. METHODS: Blood sampling was done in 30 patients with PLE [seeking or not seeking 311-nm ultraviolet (UV)B photohardening] as well as 19 healthy controls at two time points: TP1, March to June (before phototherapy); and TP2, May to August (after phototherapy). We compared the number of CD4(+) CD25(high) CD127(-) FoxP3(+) Tregs by flow cytometry and their function by assessing FoxP3 mRNA levels and effector T cell/Treg suppression assays. RESULTS: Tregs isolated from healthy controls significantly suppressed the proliferation of effector T cells at TP1 by 68% (P = 0·0156). In contrast, Tregs from patients with PLE entirely lacked the capacity to suppress effector T-cell proliferation at that time point. The medical photohardening seen in 23 patients with PLE resulted in a significant increase in the median percentage of circulating Tregs [both as a proportion of all lymphocytes; 65 6% increase (P = 0·0049), and as a proportion of CD4(+) T cells; 32.5% increase (P = 0·0049)]. This was accompanied by an increase in the expression of FoxP3 mRNA (P = 0·0083) and relative immunosuppressive function of Tregs (P = 0·083) comparing the two time points in representative subsets of patients with healthy controls tested. Seven patients with PLE not receiving 311-nm UVB also exhibited an increase in the number of Tregs but this was not statistically significant. No significant differences in Treg numbers were observed in healthy subjects between the two time points. CONCLUSIONS: An impaired Treg function is likely to play a role in PLE pathogenesis. A UV-induced increase in the number of Tregs (either naturally or therapeutically) may be a compensatory mechanism by which the immune system counteracts the susceptibility to PLE.

Skin hardening effect in patients with polymorphic light eruption: comparison of UVB hardening in hospital with a novel home UV-hardening device.

BACKGROUND: An effective prophylactic treatment of patients with polymorphic light eruption (PLE) consists of repeated low, gradually increasing exposures to UVB radiation. This so-called UV(B) hardening induces better tolerance of the skin to sunlight. OBJECTIVE: SunshowerMedical company (Amsterdam) has developed an UV (B) source that can be used during taking shower. The low UV fluence of this apparatus makes it an interesting device for UV hardening. In a group of PLE patients, we compared the effectiveness of the irradiation with SunshowerMedical at home with that of the UVB treatment in the hospital. METHODS: The PLE patients were randomized for one of the treatments. The hospital treatment consisted of irradiations with broad-band UVB (Waldmann 85/UV21 lamps) twice a week during 6 weeks. The home UV-device was used each day with the maximal irradiation time of 6 min. The outcome assessment was based on the information obtained from patients' dermatological quality of life (DLQI) questionnaires, the ability of both phototherapies to reduce the provocation reaction and from the patients' evaluation of the long-term benefits of their phototherapies. RESULTS: Sixteen patients completed treatment with SunshowerMedical and thirteen completed treatment in hospital. Both types of phototherapy were effective. There was a highly significant improvement in DLQI with either treatment. In most cases, the hardening reduced or even completely suppressed clinical UV provocation of PLE. The patients using SunshowerMedical at home were, however, much more content with the treatment procedure than the patients visiting the dermatological units. CONCLUSIONS: Both treatments were equally effective in the induction of skin tolerance to sunlight in PLE patients. However, the home treatment was much better accepted than the treatment in the hospital.

[Lasers]. / Lasers.

Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients.

Phototolerance induced by narrow-band UVB phototherapy in severe erythropoietic protoporphyria.

Erythropoietic protoporphyria arises from an inherited disorder of porphyrin metabolism which leads to an accumulation of protoporphyrin IX in the erythropoietic system and other tissues. It is characterized by cutaneous photosensitivity, usually difficult to keep under control. Among the scant therapeutic options proposed to reduce photosensitivity in erythropoietic protoporphyria, narrow-band UVB phototherapy has occasionally been used to induce sunlight tolerance. We report an adult case of erythropoietic protoporphyria with a severe photosensitivity treated with narrow-band UVB that developed an appropriate sunlight phototolerance, without adverse events during phototherapy.

Patients with polymorphic light eruption have decreased serum levels of 25-hydroxyvitamin-D3 that increase upon 311 nm UVB photohardening.

BACKGROUND: Polymorphic light eruption (PLE) is a very common condition whose pathogenesis may involve immunological abnormalities. Vitamin D sufficiency is thought to be important for normal immune function. OBJECTIVE: To determine whether PLE patients are vitamin D deficient and to study how photohardening with 311 nm UVB affects the vitamin D status of PLE patients. METHODS: The vitamin D status of 23 PLE patients (21 females and 2 males; age range, 18-55 years) was analysed at four different time points (early spring, late spring, summer, and winter) by measuring 25-hydroxyvitamin-D(3) (25(OH)D) serum levels through a standardised immunoassay. Fifteen of those patients received 311 nm UVB in early spring for prevention of PLE symptoms. 25(OH)D levels of the PLE patients were compared to that of 23 sex-, age-, and body-mass-index post hoc-matched control subjects. RESULTS: PLE patients had low levels of 25(OH)D throughout the year compared to that of the control subjects. At baseline in early spring, the mean ± SD 25(OH)D level was 14.9 ± 3.0 ng ml(-1) in the PLE patients that would later receive 311 nm UVB and 14.4 ± 2.4 ng ml(-1) in the patients not receiving 311 nm UVB. Successful prophylactic treatment with 311 nm UVB significantly increased 25(OH)D levels to a mean of 21.0 ± 3.4 ng ml(-1) (p < 0.001; ANOVA, Tukey's test). Heading into summer, the 25(OH)D levels in treated patients decreased again, reaching their lowest levels in winter. In contrast, the 25(OH)D levels of untreated PLE patients stayed in the low range in early and late spring but increased by trend towards summer, reaching similar levels to that of the PLE patients who had received 311 nm UVB (17.1 ± 2.3 vs. 17.3 ± 6.0 ng ml(-1)). Like the treated PLE patients, 25(OH)D levels of untreated patients significantly decreased in winter to comparable levels (12.2 ± 1.9 vs. 13.8 ± 1.8 ng ml(-1)). Taken together, the 25(OH)D levels of PLE patients were significantly lower at all time points than that observed in the matched control population (34.4 ± 12.5 ng ml(-1)) (p < 0.000003). CONCLUSIONS: PLE patients have low 25(OH)D serum levels. 311 nm UVB phototherapy that prevented PLE symptoms increased those levels. Thus, we speculate that boosting levels of vitamin D may be important in ameliorating PLE.

Successful and long-lasting treatment of solar urticaria with ultraviolet A rush hardening therapy.

BACKGROUND: Solar urticaria (SU) is a photodermatosis that is thought to be caused through the effects of mast cell mediators released because of an altered chromophore, possibly a photoallergen recognized by IgE. Phototherapy for SU to induce a tolerant state appears to be most effective, but is often time consuming and provides only short-lived remission. Ultraviolet (UV) A rush hardening has been successful and less time consuming in serum factor-negative patients with SU. However, the mechanism of action and long-lasting effects of UVA rush hardening therapy remain unclear. OBJECTIVES: We aimed to evaluate whether UVA rush hardening exhibits long-lasting therapeutic effects in serum factor-positive patients with SU and to examine the action mechanism of tolerance. METHODS: Two serum factor-positive patients with SU were exposed to multiple UVA irradiations at 1-h intervals per day for 2 or 3 days. Intradermal injection of their in vitro-irradiated autologous serum or compound 48/80 and a prick test for histamine were performed before and after UVA rush hardening. RESULTS: The two serum factor-positive patients with SU benefited greatly from UVA rush hardening, as documented by a marked increase in minimal wealing dose, and remained symptom free without using sunscreen in their daily life. Intradermal injection of in vitro-irradiated autologous serum induced wealing before hardening, but not in tolerized skin after hardening. The responses to compound 48/80 and histamine were unaltered. CONCLUSIONS: UVA rush hardening is an effective and long-lasting treatment even in serum factor-positive patients with SU. The mechanism of tolerance may involve continued blockade of photoallergen binding to IgE on mast cells, rather than depletion of mast cell mediators or histamine tachyphylaxis.

Narrowband ultraviolet B phototherapy is a suitable treatment option for solar urticaria.

BACKGROUND: Narrowband (NB) ultraviolet (UV) B lamps are widely used for treatment and prophylaxis of several skin diseases. OBJECTIVE: We sought to assess the efficacy of two protocols of NB-UVB therapy for the prophylaxis of UVB-sensitive and UVB-insensitive solar urticaria (SU). METHODS: Subjects affected by SU underwent phototesting for assessment of the minimal erythemal dose and minimal urticarial dose. Patients without urticarial response to UVB underwent a single daily exposure every other day for 4 weeks (group A). Patients with a urticarial test response to broadband UVB or NB-UVB (group B) received 3 daily exposures (on working days) for the first week. Afterward, they were treated as the patients of group A for 3 weeks. Follow-up visits took place after 1 and 3 months. RESULTS: A total of 39 patients completed the study. In groups A (29 patients) and B (10 patients), the median total number of exposures was 12 (interquartile range [IQR]: 12; 15) and 25.5 (IQR 24; 27), respectively. The median total NB-UVB dose was 10.3 J/cm(2) (IQR 9.9; 11) for group A and 9.1 J/cm(2) (IQR 8.5; 10.6) for group B. At follow-up visits, patients reported good tolerance to the sun. LIMITATIONS: A direct comparison of NB-UVB with UVA or psoralen plus UVA for the photoprophylaxis of SU is still lacking. CONCLUSION: NB-UVB phototherapy was well-tolerated and effectively prevented SU relapses.

Chronic actinic dermatitis: two patients with successful management using narrowband ultraviolet B phototherapy with systemic steroids.

BACKGROUND: Chronic actinic dermatitis (CAD) is a debilitating photodermatosis with characteristic clinical, histological and photobiological features (reduced minimal erythema dose: MED). Its management involves various therapeutic approaches, among them there is phototherapy. Efficacy of psoralen ultraviolet therapy (PUVA therapy) was previously demonstrated but there are no current data on the use of narrowband ultra violet B (UVB) therapy (NB-UVB) in CAD. NB-UVB has already been proven to be effective and safe in several other photodermatoses. CASE REPORTS: We report here two dark-skinned patients (skin type IV and V) with CAD, successfully treated with an incremental regimen of NB-UVB phototherapy coupled to a 3 month-course of systemic steroids (1mg/Kg/day). CONCLUSION: Our protocol of NB-UVB with steroids seems to be effective for the management of CAD with a good short term safety profile.

Italian position paper on urticaria. Italian Board on Urticaria.

The Italian Board on Urticaria has prepared a document focusing on the definition and classification of urticaria, taking into account the recent progress in identifying the causes, eliciting factors, and pathomechanisms of this disease. As urticaria has a profound impact on the quality of life, effective treatment is important. Therefore, specific treatment options for the management of urticaria are evaluated on the basis of the recent literature. Non-sedating H(1) antihistamines are recommended as the first-line treatment as they have proven effective in several randomized double-blind controlled studies. Dosages higher than those recommended may be necessary in some cases. However, additional or alternative therapies may be required for different urticaria subtypes and in view of individual variations in the course of the disease and response to treatment. Immunosuppressive drugs such as corticosteroids are not recommended for long-term treatment due to unavoidable, severe adverse effects.

Treatment of poikiloderma of Civatte with the pulsed dye laser: a series of patients with severe depigmentation.

BACKGROUND: Pulsed dye laser (PDL) treatment is widely used for poikiloderma of Civatte. Some adverse events in small numbers of patients have been reported. Guidelines for treatment of poikiloderma of Civatte do not exist. OBJECTIVE: To report the occurrence of persistent depigmentation as a late adverse event in a series of patients with poikiloderma of Civatte after treatment with PDL. METHODS: Eight patients (seven women and one man, mean age 48 years) with poikiloderma of Civatte were treated with PDL using a 585-nm wavelength and a fixed pulse duration of 450 micros. In all patients one or two test PDL patches were performed and reviewed after 3 months. All of the patients tolerated the testing without complications. Subsequent treatments were undertaken at intervals of 3 months. RESULTS: All patients were treated with fluences between 3.5 and 7 J/cm2, using a 7- or 10-mm spot size. All patients had a good result with respect to clearing of the vascular component. Nevertheless, six of them, treated with 5-7 J/cm2, reported severe depigmentation 4-11 months after treatment. Two patients treated with lower fluences (3.5-5.5 J/cm2) did not report this depigmentation. CONCLUSIONS: Great care is needed when PDL treatment is used for poikiloderma of Civatte. Pigment changes have been incidentally mentioned as late complications but have not been well documented as the late depigmentation has been in this series. It is advisable to use fluences as low as possible, and not exceeding an upper limit of 5 J/cm2, on a 10-mm spot size. More research is needed to define an optimal pulse duration.

Laser-mediated photodynamic therapy of actinic keratoses.

OBJECTIVE: To assess the safety and efficacy of the long-pulsed pulsed dye laser (LP PDL) (595 nm) with photodynamic therapy (PDT) for treatment of actinic keratoses (AKs). DESIGN: Prospective, controlled study with 10-day and 2-, 4-,6-, and 8-month follow-ups. SETTING: Clinical research center. PATIENTS Volunteer sample of 41 patients (age range, 35-91 years; skin types I-III) with AKs. INTERVENTION: Single treatment with application of topical 20% 5-aminolevulinic acid for 3 hours or 14 to 18 hours, followed by LP PDL irradiation at 595 nm. Controls received LP PDL irradiation alone. MAIN OUTCOME MEASURES: Safety assessments, treatment and recovery times, and efficacy assessments, including patient mean percentage of lesions cleared and distribution of patients by percentage of lesions cleared for different anatomic sites. RESULTS: We observed no to slight pain; slight to moderate erythema; no purpura, crusting, or scarring; treatment time of 1 lesion per second; and resolution of erythema by 7 to 14 days. The patient mean (95% confidence interval) percentage of head lesions (2620 lesions) cleared after 1 treatment was 99.47% (99.44%-99.50%) at 10 days, 98.19% (98.15%-98.23%) at 2 months, 92.94% (92.73%-93.14%) at 4 months, 91.65% (91.15%-92.15%) at 6 months, and 90.32% (78.10%-100%) at 8 months. For extremities (949 lesions), these were 83.1% (81.4%-84.9%) at 10 days, 75.5% (73.4-77.6) at 2 months, 70.9% (68.9%-72.8%) at 4 months, 92.0% (84.0%-100%) at 6 months, and 100% at 8 months. For trunk (53 lesions), these were 85% (74%-100%) at 10 days, 85% (74%-100%), and 65% (50%-80%) at 4 months. No difference in safety or efficacy was found between the 3-hour and 14- to 18-hour incubation times. In the laser-only control group, no decrease in lesions was observed. Among 31 patients with head lesions, 28 (90%) at 10 days, 19 (70%) at 2 months, 9 (47%) at 4 months, 5 (42%) at 6 months, and 5 (56%) at 8 months were completely (100%) clear following a single treatment. Skin biopsy specimens of nonresponding lesions demonstrated a high rate of squamous cell carcinoma and other non-AK neoplasms. CONCLUSIONS: Treatment of AKs using LP PDL (595 nm) at nonpurpuric parameters following topical application of 5-aminolevulinic acid is safe and effective. The advantages may include minimal discomfort, rapid incubation treatment and recovery times, excellent posttreatment cosmesis, high efficacy rates with respect to head lesions, and practical applicability to large body surface areas.

Fotoerupción cutánea en infección VIH avanzada / Cutaneous photoeruption in advanced HIV infection

Describimos el caso de una mujer de raza blanca, VIH positiva, que inició erupción cutánea fotosensible coincidiendo con el deterioro de su situación inmune marcada por la disminución de linfocitos CD4 y elevada carga viral. Su evolución clínica fue paralela a la inmunitaria con importante mejoría después de recibir triple tratamiento antiretroviral. Discutimos los aspectos patogénicos de estas fotoerupciones que pueden suponer un marcador clinico de la infección VIH y su progresión. Comentamos la importancia del control de la radiación ultravioleta y puvaterapia en pacientes VIH positivos (AU)

[Solar urticaria: pre-PUVA UVA desensitization]. / Urticaire solaire : désensibilisation UVA avant PUVAthérapie.

BACKGROUND: Solar urticaria is an uncommon disorder sometimes difficult to treat. It is characterized by the occurrence of typical whealing reactions on exposed skin a few minutes after sun exposure. The reactions resolve 1 to 5 hours after sun exposure ceases. We report a case evolving over several years, unresponsive to antihistamines and successfully treated by PUVAtherapy performed after UVA desensitization. CASE REPORT: For 3 years, a 22-year-old man developed erythema and itchy wheals at each solar exposure. The lesions appeared on all exposed areas including those usually exposed (face and hand) even in winter. An antihistamine regimen given for several weeks (cetirizine, loratadine) was ineffective. One trial of PUVA therapy led to an urticarial reaction of the entire body. Phototesting showed the minimal whealing dose for UVA was 0.4 J/cm(2). Phototherapy was therefore started by segmentary UVA irradiation at an initial dose of 0.1 J/cm(2). Exposure was then progressively increased allowing initiation of the PUVAtherapy on the 9(th) day with a dose of 0.5 J/cm(2) without whealing reaction. Slow increment PUVA therapy was able to induce good tolerance to sun exposure. DISCUSSION: Solar urticaria may sometimes have a deleterious effect on normal daily life. Severe cases are characterized by a whealing reaction after minimal sun exposure, even on regularly exposed skin. Antihistamines can provide some symptom relief in many patients, but high doses are required. If antihistamines are ineffective, PUVA therapy is indicated. Pre-PUVA UVA desensitization is often necessary. However, exposure to UVA alone has to be repeated every 24 to 48 hours to maintain the refractory state. The advantage of PUVA therapy is a more long lasting protection allowing weekly maintenance sessions.