BCG Scar Reactivation During Influenza Infection in the Absence of Kawasaki Disease: A Primary Care Case Report.

BCG scar reactivation is classically associated with Kawasaki disease but may also occur during immune activation caused by infections. We report a 26-month-old boy with laboratory-confirmed influenza B who developed transient erythema and swelling at a previous BCG vaccination scar without clinical features of Kawasaki disease or MIS-C. The scar reaction regressed with symptomatic treatment and oseltamivir as influenza symptoms improved. This case highlights that BCG scar reactivation is not specific to Kawasaki disease and should be interpreted within the full clinical context to avoid unnecessary investigations while maintaining appropriate follow-up.