Not Just Another Facial Abscess: Cervicofacial Actinomycosis Uncovered by Skin Biopsy.

Cervicofacial actinomycosis is a rare, chronic bacterial infection that typically arises after mucosal disruption, often due to dental procedures. We present the case of an 18-year-old female patient with a persistent erythematous cheek nodule following wisdom tooth extraction. Initial imaging was non-specific, and prior treatment was deferred due to diagnostic uncertainty. A punch biopsy revealed sulfur granules and histologic features consistent with actinomycosis, though molecular testing detected only commensal flora. Initiation of targeted antibiotic therapy led to clinical improvement. This case underscores the diagnostic value of dermatologic biopsy in atypical post-dental lesions and highlights the limitations of molecular diagnostics in isolating Actinomyces.