[Hypersensitivity pneumonia caused by sulfonamides].

A 59-year-old man with Duhring's disease (herpetiform dermatitis) developed undulating fever and pulmonary infiltrates soon after sulfapyridine treatment was started. When the drug was discontinued, a positive provocation test unequivocally established the diagnosis of hypersensitivity pneumonia. There was also a cross-reaction with sulfonyldianiline (dapsone). This case illustrates the need of considering a hypersensitivity reaction as the cause of fever and (or) pulmonary infiltration during sulphonamide administration.