Delayed Presentation of Anticonvulsant Hypersensitivity Syndrome Secondary to Lamotrigine

Anticonvulsant hypersensitivity syndrome (AHS) is a rare condition that needs to be seriously recognized and diagnosed. However, it is difficult to diagnose it since its clinical manifestation mimics other common infectious and neoplastic diseases. AHS manifests as skin rash that is preceded by fever accompanying internal organ involvement, with the liver being mostly affected. AHS is a condition that develops secondary to anticonvulsant exposure like phenytoin, phenobarbitone, carbamazepine, and lamotrigine. A defect in epoxide hydroxylase leading to the accumulation of toxic metabolites of aromatic anticonvulsant is hypothesized to play a role in developing AHS. This report presents a case of a 49-year-old epileptic Asian female, who complained of persistent high-grade fever followed by generalized maculopapular rash, high liver enzymes, and pancytopenia. The patient had unremarkable past history and systematic review. The patient went through various investigations to rule out infections and systematic diseases and all investigations were normal. After excluding every possible cause, the patient was diagnosed with AHS secondary to lamotrigine usage for one month.