A case report of reversible left ventricular dysfunction due to azathioprine hypersensitivity syndrome.

Hypersensitivity reaction with cardiac involvement due to AZA is rare. The exact mechanisms underlying AZA-related cardiac dysfunction are still not completely understood, and causality is often difficult to prove. However, because of re-exposure to the drug, which, considered retrospectively, was inappropriate, the effect was clearly apparent in our patient. Knowledge of this potentially life-threatening side effect of AZA treatment is important. AZA must be discontinued promptly if there is any evidence of hypersensitivity reaction.