Case Report - Azathioprine-induced shock: An uncommon, unpredictable and potentially fatal adverse effect of azathioprine

A 60 year-old male was initiated on azathioprine 50 mg/day for airborne contact dermatitis. As the patient showed a satisfactory response to this initial therapy, azathioprine dose was escalated to 100 mg/day after two weeks. However, the patient started feeling unwell from that day onwards and developed features of azathioprine-induced shock leading to discontinuation of azathioprine. Within the next 24 hours, there was complete resolution of nausea, malaise, abdominal pain, hypotensive episodes, fever and diarrhea in a pattern similar to that in which they had appeared. Rechallenge with a single dose of azathioprine (50 mg), resulted in the recurrence of nausea, vomiting and the characteristic fever spike four hours later. His blood pressure showed a marginal fall from 130/80 to 100/70 mm Hg. However, a clinically manifest episode of hypotension did not develop. This case is being reported for its rarity and clinical interest.