Recurrent cutaneous vasculitis in cystic fibrosis.

We treated a patient with cystic fibrosis who experienced recurrent episodes of palpable purpura and arthralgias associated with exacerbations of her pulmonary disease. Skin biopsy demonstrated the classic findings of leukocytoclastic vasculitis, and C3 deposits were detected in the dermal blood vessels. Chronic bacterial infection and antibiotics are possible sources of antigen involved in immune complex formation in patients with chronic lung diseases.