Lip swelling the day after a biopsy

Correct answer: C. Angioedema

• A. Mechanical trauma from a clamp produces a localised bruise or laceration, not diffuse angioedematous swelling.
• B. A hematoma from the biopsy would be bruised and discoloured and localised to the surgical site rather than producing diffuse lip swelling.
• C. Correct. ANGIOEDEMA is rapid, non-pitting swelling of the deep dermis and submucosa, produced by increased vascular permeability. In the dental setting it most often follows exposure to LATEX (rubber dam, gloves), to a local anaesthetic or its preservative, or to a drug such as an ACE inhibitor. The lip is a classic site.
• D. Cellulitis is a spreading bacterial infection with erythema, warmth, tenderness and often fever — its onset is not typically abrupt overnight after a minor biopsy.

Note: ⚠️ AIRWAY ALERT. Angioedema involving the tongue, floor of mouth or larynx is a MEDICAL EMERGENCY. Management: stop the procedure, assess the airway, give epinephrine 0.3 mg IM (1:1000) if there is any airway involvement, plus an antihistamine and corticosteroid, and activate EMS. This same scenario appears elsewhere in this file as lip swelling after removing the rubber dam — a strong pointer to LATEX allergy.