Severe Cutaneous Adverse Reaction to Intraperitoneal Vancomycin: A Case of DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms) Syndrome.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome is a rare but potentially life-threatening hypersensitivity reaction to certain medications, including allopurinol (a xanthine oxidase inhibitor), antiepileptics (e.g., phenytoin, carbamazepine), and antibiotics (e.g., vancomycin). It typically presents within 2-12 weeks after administration of the offending drug. DRESS causes a characteristic rash, fever, renal alterations (acute kidney injury with associated findings of hematuria and proteinuria), hematologic alterations (eosinophilia, leukocytosis with the presence of atypical lymphocytes, and occasionally anemia or thrombocytopenia), and hepatic involvement, which represents the main organ manifestation, characterized by hepatitis with elevated transaminases. It is a potentially life-threatening multiorgan disorder. Although vancomycin is a known causative agent, DRESS associated with intraperitoneal vancomycin remains extremely rare. We report the case of a 59-year-old male with a history of type 2 diabetes, benign prostatic hyperplasia, systemic arterial hypertension, and KDIGO (Kidney Disease: Improving Global Outcomes) stage 5 chronic kidney disease, on peritoneal dialysis via a Tenckhoff catheter, who developed generalized dermatosis, systemic symptoms, and laboratory findings consistent with DRESS, 25 days after initiating intraperitoneal vancomycin for bacterial peritonitis. We performed a detailed clinical examination of the pruritic, violaceous maculopapular rash presented by the patient, along with laboratory analysis, which showed eosinophilia, elevated liver enzymes, and atypical lymphocytosis on peripheral blood smear. The diagnosis was confirmed using the Registry of Severe Cutaneous Adverse Reactions (RegiSCAR) scoring system and supported by histopathological findings from a skin biopsy, which revealed lymphocytic and eosinophilic inflammation. The patient responded favorably to withdrawal of the drug, as well as systemic corticosteroid therapy, with both clinical and laboratory improvement. This case highlights the need to consider intraperitoneal vancomycin as a potential trigger for DRESS, particularly in patients with impaired renal clearance. Prompt recognition, withdrawal of the offending agent, and initiation of immunosuppressive therapy are essential to reducing morbidity and preventing severe complications.