Refractory livedoid vasculitis responding to PUVA: a report of four cases.

Livedoid vasculitis is a chronic disease characterized by recurrent painful irregularly shaped ulcers, which heal with scars, most commonly located on feet or lower extremities. This condition is often resistant to the therapy. We report four cases with refractory livedoid vasculitis that responded to systemic psoralens and ultraviolet A radiation therapy.

Fixed solar urticaria induced by UVA and visible light: a report of a case.

Fixed solar urticaria (FSU) is a rare and less severe subgroup of solar urticaria. It is characterized by urticarial eruptions, which occurs on the same parts of the body following sun exposure. The lesions are reproducible at the same sites with similar morphology and distribution pattern after repeated sun exposure. The action spectrum of FSU is broad (300-700 nm). We reported a case of FSU induced by UVA and visible light. The patient responded well to cetirizine treatment.

Comparison of phototherapy two times and four times a week with low doses of narrow-band ultraviolet B in Asian patients with psoriasis.

BACKGROUND/AIMS: The optimum narrow-band (TL-01) ultraviolet (UV) B weekly treatment frequency for psoriasis has yet to be defined, especially in Asian patients with TL-01. Our purpose was to compare 2 x weekly and 4 x weekly therapy with narrow-band UVB at low doses for psoriasis vulgaris. METHODS: Sixty-nine patients with moderately severe psoriasis were recruited and allocated to the 2 x weekly or 4 x weekly treatment group. The patients were treated with a new protocol using low doses of narrow-band UVB with varied exposure increments. Outcomes were evaluated by means of Psoriasis Area and Severity Index (PASI) scores, time (weeks), cumulative UVB dose and number of treatments to clearance. RESULTS: No significant difference was found between the two regimens in the PASI score at the end of treatment, in the proportion of patients whose skin cleared during treatment and in the time to clearance (8 weeks). Those who completed treatment achieved clearance after a median of 16 exposures with 2 x weekly treatment compared with 32 exposures with 4 x weekly treatment (P=0.0304), and 12.5 minimal erythema dose multiples (MEDs) compared with 39.7 MEDs (P=0.0470). Acute side effects of the treatment were similar for the two groups (P=0.8462). CONCLUSION: For skin phototype III-V populations, a greater long-term risk is expected, connected with the higher cumulative UVB dose and number of exposures required in the 4x weekly group. Therefore, 4 x weekly phototherapy will no longer be used for psoriasis.

A comparison of erythema efficacy of ultraviolet B irradiation from Philips TL12 and TL01 lamps.

The erythema efficacy of UVB irradiation from Philips TL12 and TL01 lamps has been evaluated and compared. Thirty-seven healthy Thai volunteers were irradiated on the previously unexposed lower back with TL12 and TL01 lamps in doses ranging 100 to 550 mJ/cm2 and 360 to 2020 mJ/cm2, respectively. Erythema was evaluated clinically and measured by a narrow-band spectrophotometer before exposure and 24 h after exposure. The threshold doses of UVB that induced barely perceptible erythema (MEDb) with well-defined border erythema (MEDw) and the steepness of the dose-response curves for erythema (DRAE) were compared. We found that MEDb and MEDw of the TL01 lamps were 4.19 and 4.52 times those of TL12 lamps, which were similar to those calculated from the CIE erythema action spectrum (4.2). However, the DRAE of the two lamps were quite similar. Because the initial dosage of UVB phototherapy is usually given as a percentage of a patient's MED, the initial exposure of TL01-UVB phototherapy should be about 4.2 times that of TL12-UVB.