Treatment of refractory solar urticaria with plasma exchange.

Background: Solar urticaria is a photodermatosis that can be very disabling for patients who are highly sensitive to light and can also be very resistant to therapy.

Objective: To correlate the results of serial phototesting in a patient with severe and refractory solar urticaria before and after treatment with plasma exchange.

Methods: Plasma exchange was performed five times over a period of 10 days. Phototesting to ultraviolet A (UVA) irradiation and visible light was performed with fluorescent ultraviolet tubes and an incandescent lamp.

Results: The urticaria that developed after very low light doses during baseline phototesting could not be provoked following plasma exchange. The patient is now almost symptom-free, with only occasional and transient hives more than 21 months after her last plasma exchange.

Conclusions: Plasma exchange is a therapeutic modality to consider in highly light-sensitive patients when other treatments have failed.