Solar urticaria: long-term rush hardening by inhibition spectrum narrow-band UVB 311nm

Abstract

Conflict of interest: none declared. Idiopathic solar urticaria (SU) constitutes a severe and potentially life‐threatening photos induced disease, and usually represents a therapeutic challenge that may not be manageable by antihistamines or sun protection only.1 Each case of SU presents with sensitivity to individual ultraviolet (UV) light spectra, which trigger urticarial lesions. We present the case of a patient with SU with sensitivity to both visible light and UVA1, who was treated effectively with a narrow‐band (NB)‐UVB regimen. A 25‐year‐old man with Fitzpatrick skin type II presented with a 1‐month history of severe generalized SU for months before admission. After a session of sunbathing, he had experienced dizziness, nausea and grade II anaphylaxis‐like symptoms. Urticarial lesions had also been provoked indoors by glass‐filtered sunlight. Sunscreens with high levels of UVA and UVB protection, oral antihistamines, and steroids had little effect. Laboratory investigations showed normal results for serum tryptase, porphyrin levels in faeces and for blood cell count, including numbers of erythrocytes and mast cells, routine serum and urine analysis, and levels of C‐reactive protein, antinuclear antibodies, double‐stranded DNA antibodies, and total serum IgE.