Abstract
Erythema multiforme (EM) is an immune-mediated condition that manifests as targetoid skin lesions and can be triggered by various factors, including infections and vaccinations. This case report describes a 41-day-old full-term male infant who developed widespread annular, bullseye-shaped erythematous skin lesions one week after receiving the Bacillus Calmette-Guérin (BCG) vaccination. The infant, exclusively breastfed and without a significant past medical history, presented with these lesions but no associated systemic symptoms. Physical examination revealed characteristic targetoid lesions, sparing the face, palms, soles, and mucous membranes. Laboratory tests, including a complete blood count and infection markers, were within normal ranges except for a mildly elevated C-reactive protein. The differential diagnosis ruled out other conditions and EM diagnosis is confirmed. The infant was managed conservatively with supportive care, and the lesions resolved without the need for antibiotics or any additional therapy. The patient remained stable and was discharged with instructions for monitoring and follow-up. So this case highlights the importance of distinguishing EM from other similar conditions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and urticaria.