A patient returns the day after a biopsy with a swollen lip. Which is the most likely diagnosis?

Localized lip swelling appearing after a procedure/medication exposure is most consistent with angioedema (a localized, often allergic or drug-related swelling).Other options: Anaphylaxis involves systemic airway/cardiovascular compromise, not isolated lip swelling; cellulitis presents with spreading infection signs; isolated swelling is not typical normal healing.Key exam takeaway: Isolated lip swelling after exposure = angioedema; watch for airway involvement and treat accordingly.