Hypocomplementemic urticarial vasculitis: report of a 12-year-old girl with systemic lupus erythematosus.

Urticarial vasculitis, a form of leukocytoclastic vasculitis involving the postcapillary venules, is classified as a type III hypersensitivity reaction and has been associated with connective tissue disease. The lesions resemble urticaria and typically persist for more than 24 hours. Urticarial vasculitis usually affects young women, and the diagnosis is confirmed at histologic examination. Patients with urticarial vasculitis can be divided into 2 types--those with normal complement levels and those with hypocomplementemic urticarial vasculitis (HUV). Patients with normocomplementemic urticarial vasculitis have a milder course than do patients with HUV, a condition that has a strong association with systemic lupus erythematosus. Angioedema, ocular inflammation, obstructive lung disease, and glomerulonephritis are commonly associated with HUV. We describe the case of a girl with systemic lupus erythematosus and HUV who also had pancreatitis, hypothyroidism, and elevated levels of antiphospholipid antibodies.