1505: Vancomycin-Induced Dress Syndrome Presenting With Shock and Multiorgan Involvement

Introduction: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare, potentially life-threatening hypersensitivity reaction. It is classically associated with antiepileptics, but vancomycin has recently emerged as a high-risk drug in hospitalized patients. Description: A 77-year-old woman with seizure disorder and recent MRSA osteomyelitis treated with a 6-week course of vancomycin presented one week after completing antibiotics with progressive lethargy, reduced oral intake, and diffuse rash. In the ED, she was found to be hypotensive, hypoxic, and confused. She was intubated for airway protection and admitted to the ICU for vasopressor support and stress-dose steroids. Exam revealed a widespread morbilliform rash with bullae but no mucosal involvement. Lab evaluation showed leukocytosis (19,410/µL) with eosinophilia (12%), creatinine 2.1 mg/dL (baseline 0.9), and transaminitis. Skin biopsy revealed spongiotic dermatitis with eosinophils and focal dyskeratosis. RegiSCAR score was 5 (fever, eosinophilia, organ involvement, timing, biopsy findings), indicating probable DRESS syndrome. No other drug triggers were identified. The patient improved with IV hydrocortisone, was extubated on ICU day 4, and transitioned to high-dose oral prednisone with a 12-week taper. She resumed levetiracetam at discharge after neurology review. Discussion: DRESS syndrome is a severe cutaneous adverse reaction characterized by delayed onset (2–6 weeks), eosinophilia, and systemic organ involvement. While classically linked to anticonvulsants, sulfonamides, and allopurinol, vancomycin is increasingly recognized as a cause, with over 50 cases now described. ICU admission is often required for hemodynamic instability, organ failure, or airway protection. The RegiSCAR score supports diagnosis, but exclusion of mimics such as sepsis or SJS/TEN is essential. Treatment includes systemic corticosteroids for severe cases and supportive care. This case reinforces the importance of recognizing delayed hypersensitivity reactions even after completion of therapy, and highlights vancomycin as a high-risk agent for DRESS.