Solar urticaria: a time-extended retrospective series of 61 patients and review of literature

Abstract

Background: Solar urticaria is a rare, disabling, chronic disease. Few large series are available.

Objective: To report the epidemiological, clinical, phototesting, treatment and patient outcome data of a large series.

Methods: Data from 61 patients' files were retrospectively retrieved in a tertiary referral centre.

Results: 43 women and 18 men were included (mean age at first symptoms: 34 y). 3 patients had a medical history of chronic urticaria and 29% of atopy. Urticaria occurred before the 15(th) minute of sun-exposure in 95% of the patients and resolved spontaneously after its interruption within 1h in 76.4%. Determination of the action spectra revealed UVA sensitization in 91.8% of the patients, alone (49.2%) or with UVB (24.6%) or visible light (14.75%). 61.7% of the patients received antihistamines, 75% noted a significant improvement. 36.2% benefited from UVA phototherapy and were satisfied. 3 patients reported complete remission after 4 to 11 years.

Conclusions: Our study is the second largest in the literature. Main discrepancies with previous series concern the absence of associated photodermatoses and the predominance of UVA sensitization over visible light, which could be explained by suboptimal phototesting in the most ancient cases. Interpretation of our results is restricted because data were missing in 10 to 25% of the patients' files. The response to treatment was evaluated upon the dermatologist's observation, which highlights the need of validated tools to evaluate patients' disability and response to treatment.

Keywords: phototesting; solar urticaria.