Hypersensitivity syndrome due to 2 anticonvulsant drugs

Drug-induced hypersensitivity syndrome is a multiorgan-system reaction characterized by fever, pleomorphic eruption, lymphadenopathy, eosinophilia, lymphocytosis and hepatitis. We report a drug hypersensitivity syndrome in a 6-year-old Tunisian child treated for epileptic absences with sodium valproate and ethosuximide. Imputability of these 2 drugs is probable because of the chronological and clinical features. Positive rechallenge with ethosuximide confirmed the toxicity of this drug. Sodium valproate was also responsible because patch testing was positive and followed by a generalized eruption. Human herpesvirus 6 (HHV6) antibody titers increased significantly within 15 days. There was a favourable outcome after discontinuation of the drugs and corticosteroid therapy. Our case is interesting because this drug hypersensitivity syndrome occurred with non-aromatic anticonvulsant drugs. It is the 1st case with ethosuximide and the 2nd with sodium valproate. We also observed a reactivation of HHV6 infection that may contribute to the development of this hypersensitivity syndrome.