Azathioprine hypersensitivity in a renal transplant recipient

Hypersensitive reactions to azathioprine have been reported infrequently, and always in nontransplanted patients. Here, a renal transplant recipient with a severe hypersensitive reaction to azathioprine is described. We suggest that, until recently, hypersensitivity to azathioprine was suppressed in transplant recipients by the association of high doses of corticosteroids. Since the introduction of cyclosporin, azathioprine therapy is usually associated with corticosteroids in a much lower dose, so an increasing occurrence of azathioprine hypersensitivity in transplanted patients might be expected.