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.