HUMAN-HERPESVIRUS-6 INFECTION AS A RISK FACTOR FOR THE DEVELOPMENT OFSEVERE DRUG-INDUCED HYPERSENSITIVITY SYNDROME

Background: Drug-induced hypersensitivity syndrome is characterized by a severe, potentially fatal, multiorgan hypersensitivity reaction tha t usually appears after prolonged exposure to certain mugs. Its delaye d onset and clinical resemblance to infectious mononucleosis suggest t hat underlying viral infections may trigger and activate the disease i n susceptible individuals receiving these drugs. Observations: A 60-ye ar-old woman developed an itchy, generalized, erythematous, confluent rash on the 39th day of receiving allopurinol therapy. Even after sl-l e discontinued treatment with allopurinol, her skin lesions progressed to a severe blistering skin eruption. After the patient started oral prednisone therapy, her skin lesions resolved with desquamation. After complete resolution, rechallenge with allopurinol led to the developm ent of an erythematous eruption. Titers of human herpesvirus 6 IgG ant ibodies dramatically increased with the development of the eruption. T he results of a polymerase chain reaction and in situ hybridization in dicated the presence of human herpesvirus 6 in the skin lesions, altho ugh human herpesvirus 7 DNA was detected only by in situ hybridization . Conclusion: Reactivation of human herpesvirus 6, possibly in concert with human herpesvirus 7, can contribute to the development of a seve re drug-induced hypersensitivity syndrome.