Solar urticaria is an uncommon dermatological disease characterized by whea
ls developing within a few minutes after sun exposure and lasting a few hou
rs. We describe a man in whom wheals developed on his trunk and arms more t
han 30 min after sun exposure and lasted more than 24 h. High doses of UVA
reproduced lesions with histological features typical of urticaria. After 7
years, urticaria began to develop even in winter and without sun exposure.
Our patient is unusual in that his wheals were delayed in onset and longla
sting. The later association of idiopathic urticaria is an additional unusu
al feature.