Thiopronine-induced pemphigus vulgaris in rheumatoid arthritis.

Thiopronine, a D-penicillamine-like agent, is being prescribed increasingly for RA. Among side effects, only benign skin reactions have been mentioned to date. A single case of pemphigus erythematosus induced by this drug was recently reported. We describe here 3 other patients who developed pemphigus vulgaris during long-term thiopronine therapy and who improved after the drug was stopped.