Drug Induced Hypersensitivity Syndrome (DIHS) to carbamazepine, phenytoin, levetiracetam and quetiapine, a case of Multiple Drug Hypersensitivity (MDH) syndrome

Abstract

Cross reactivity to structurally related aromatic   anti-epileptic drugs is well known. These aromatic anti-epileptic drugs include phenytoin, phenobarbitone, carbamazepine and oxcarbazepine. Valproate, levetiracetam, clobazam and other anti-epileptics are preferred when there is history of   hypersensitivity to aromatic anti-epileptic drugs as these drugs lack the aromatic structure which has been speculated to be involved in cross reactivity. Multiple Drug Hypersensitivity (MDH) syndrome is a distinct clinical entity wherein there is hypersensitivity to two or more structurallychemically and  pharmacologically different drugs. This report describes an  unusual case of drug induced hypersensitivity syndrome to phenytoin, carbamazepine, levetiracetam and quetiapine in a 26 year old G2P1L1 patient with seizure disorder. While phenytoin and carbamazepine have a common aromatic structure,  levetiracetam and quetiapine have no structuralchemical   similarity. This picture closely resembles that of MDH, management of which is challenging in a pregnant patient.