Hypocomplementemic urticarial vasculitis syndrome: an interdisciplinary challenge.

BACKGROUND Chronic urticaria often points the way to the diagnosis of a systemic disease, particularly when urticarial vasculitis can be demonstrated. Hypocomplementemic urticarial vasculitis syndrome (HUVS) is considered to be an independent immunological disease. METHOD Selective literature review and consideration of the author's own clinical experience. RESULTS AND CONCLUSIONS The main manifestation of HUVS is chronic urticarial vasculitis with complement deficiency and the demonstration of C1q antibody in the serum. Multiple other organs are involved, sometimes severely. The diagnosis is confirmed by skin biopsy, which reveals leukocytoclastic vasculitis as a pathogenetic correlate of this systemic disease. Although HUVS is relatively rare, the medical specialists that might encounter it-ophthalmologists, rheumatologists, nephrologists, dermatologists, general practitioners, and pediatricians-should include it in their differential diagnoses whenever appropriate. Awareness of HUVS and rational diagnostic evaluation will lessen the chance of it being misdiagnosed as another type of systemic immunological disease and will reduce superfluous diagnostic testing in patients suffering from it.