Viral rashes mimicking drug reaction with eosinophilia and systemic symptoms syndrome in children after β-lactams intake: a diagnostic challenge

In cases of skin eruptions over the course of antibiotic therapy and concomitant viral infection, differential diagnosis is often challenging. Confirming or ruling out drug hypersensitivity is not always a clear-cut question. Drug reaction with eosinophilia and systemic symptoms (DRESS) cases, for example, is classified as severe cutaneous adverse reactions due to drugs, but frequently the clinical manifestations do not completely fit into the diagnosis of DRESS. The aim of the present paper is to highlight similarities and differences among DRESS syndrome and DRESS-like rashes during viral infections and amoxicillin intake in children, in order to highlight those aspects that can help clinicians in early detection. We describe the dermatological, clinical, and laboratory characteristics of five patients hospitalized for DRESS-like skin rashes appearing roughly 1 week since the start of an amoxicillina course for upper respiratory tract infection (URTI) symptoms. The data are compared with those of 3 patients with early-onset DRESS syndrome. The absence of eosinophilia might be an initial marker to help identifying DRESS-like rashes; a quick clinical improvement and the confirmation of a viral infection able to explain the symptoms can help to finally rule out DRESS syndrome.

Conclusion: A rapid, correct diagnosis of such DRESS-like rashes during viral infections allows more appropriate management and avoids unnecessary, life-long exclusion of useful and effective antibiotics because of a falsely “amoxicillin-allergy” labelling.