Acute renal and hepatic failure associated with allopurinol treatment

Hyperuricemia is present in about 5% of the population, and allopurinol is frequently used to treat it. The use of this drug can be associated with a number of side effects, indicating allergic reactions, such as skin rash, reversible after its withdrawal. In some cases more severe hypersensitivity reactions may be seen, such as erythema multiforme exudativum, or Steven-Johnson Syndrome (SJS). Reversible clinical hepatotoxicity, as well as acute renal failure, may also develop after allopurinol therapy. We describe here the case of a 74-year-old woman with chronic renal failure who was admitted to hospital after 1 week of sore throat and fever, presenting mucous membrane lesions, widespread blistering of the skin, evolving to flaccid vesicles and bullae, and extensive epidermal detachment associated with acute renal failure and cholestatic jaundice. A diagnosis of allopurinol-induced toxic epidermal necrolysis (TEN) was established. Allopurinol was discontinued, and intensive care management was required: the patient was successfully treated by using intravenous immunoglobulin (IVIg), standard hemodialysis, and albumin dialysis (Molecular Adsorbents Recirculating System - MARS, Teraklin AG, Rostock, Germany). Allopurinol-induced TEN is extremely rare, however, the survival rate is extremely low. Clinicians should be aware of this potentially severe adverse effect. This report emphasizes the importance of an aggressive pharmacological and dialysis treatment in the case of TEN.