Early-onset serum sickness-like reaction: Role of drug provocation tests in diagnosis

Abstract

Serum sickness-like reaction (SSLR) is a rare, non-IgE-mediated hypersensitivity reaction typically occurring in early childhood, characterized by nonspecific symptoms such as rash, fever, and joint involvement. Although symptoms generally emerge 5–21 days after drug exposure, earlier onset may occur in sensitized individuals upon repeated exposure to the same agent. We report the case of a 5-year old boy who developed fever, erythema, and extremity pain within 12 hours of a drug provocation test (DPT) with amoxicillin-clavulanic acid (ACA). A second DPT performed one month later triggered similar symptoms within 3 hours, confirming the diagnosis of SSLR. Laboratory findings supported systemic inflammation, and the symptoms resolved with corticosteroid treatment. This case highlights the variability in SSLR symptom onset and emphasizes the potential utility of DPT in selected cases to confirm the diagnosis and avoid unnecessary drug elimination. It also draws attention to the need for careful patient selection and standardized protocols when performing DPT in suspected SSLR.