SEVERE HYPERSENSITIVITY SYNDROME DUE TO SULFASALAZINE ASSOCIATED WITHREACTIVATION OF HUMAN-HERPESVIRUS-6

Background: A severe adverse reaction to sulfasalazine therapy has bee n associated with hypersensitivity syndrome, the clinical features of which are similar to infectious mononucleosis. No serologic evidence o f viral infections has been reported with this syndrome; however, huma n herpesvirus 6 infection has not been specifically investigated, whic h could cause an infectious mononucleosislike syndrome. Observations: We report 2 cases of hypersensitivity syndrome induced by the use of s ulfasalazine. The clinical features of the syndrome appeared 18 and 32 days after administration of sulfasalazine. Clinical signs included a maculopapular rash progressing to exfoliative erythroderma, fever, an d lymphadenopathy. Leukocytosis, atypical lymphocytes, liver dysfuncti on, and renal disturbance were also observed. In 1 patient, human herp esvirus 6 variant B was isolated from peripheral blood mononuclear cel ls, and in both patients anti-human herpesvirus 6 IgG titers increased considerably. Conclusions: Two cases of hypersensitivity syndrome due to sulfasalazine use were associated with the reactivation of human h erpesvirus 6, which may be a required cause of hypersensitivity syndro me.