Prolonged evolution of drug reaction with eosinophilia and systemic symptoms: clinical, virologic, and biological features.

Prolonged Evolution of Drug ReactionWith Eosinophilia and Systemic Symptoms: Clinical, Virologic, and Biological Features Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare and severe drug-induced reaction characterized by systemic involvement and an unusually long latency of onset after exposure to medication. Because this syndrome is not easily identified, it remains underdiagnosed. Its physiopathological characteristics are still incompletely understood, involving reactivation of dormant herpesviruses triggered by the culprit drug.1 Moreover, herpesvirus reactivations might even have an impact on the severity and duration of DRESS.2 Usually, DRESS resolves within 1 month; however, some patients have prolonged evolution, sometimes associated with flare-ups. In addition, some patients with DRESS can develop persistent renal insufficiency or autoimmune symptoms following acute hypersensitivity events.3 Factors associated with prolonged evolution have not been identified to date. Our study aimed to assess clinical and biological features associated with prolonged evolution in a prospective cohort of 40 patients with DRESS. Methods |PatientswithDRESSwere included according to the criteriadescribed inourprevious investigation.1Thestudywas approvedbyour localethicscommittee (ClinicalTrials.gov,NCT 00213447).Writtenconsentwasobtained frompatients.Onthe basis of a study in which median duration of disease was estimated at 30 days,2 prolonged evolution was defined by the persistence, at least up to day 90, of at least 1 clinical and/or 1 laboratory abnormality. Viral DNA from Epstein-Barr virus (EBV), cytomegalovirus, andhumanherpesvirus (HHV) types 6and7wasquantifiedbymeansof real-timepolymerase chain reaction (RT-PCR) in serum and peripheral blood mononuclear cells of patients. Statistical analysis usednonparametric tests, the Wilcoxon test, and the Fisher exact test.