Sulfasalazine-induced extrinsic allergic alveolitis in a patient with psoriatic arthritis.

We report the first case of a well defined extrinsic allergic alveolitis as a complication of sulfasalazine therapy in a patient treated for psoriatic arthritis. CT of the chest showed small nodular densities over both lungs, BAL demonstrated a highly active lymphocytic alveolitis and transbronchial biopsies revealed lymphoplasmocytic interstitial infiltration. Sulfasalazine as causative agent was proven by an inadvertent rechallenge three years later and a positive lymphocyte transformation test. sulfasalazine; psoriatic arthritis; extrinsic allergic alveolitis