Purpuric rashes in cystic fibrosis.

Sixteen patients with cystic fibrosis experienced vasculitic rashes of the lower extremities that resembled hypergammaglobulinemic purpura. The rashes were associated with increased serum gammaglobulin G levels and rather severe lung disease. The rashes are probably the expression of chronic lung infection and high antigenic load in these patients. Their appearance was associated, in most cases, with poor long-term survival.