Immediately after the rubber dam is removed at the end of a procedure, a patient's lips become markedly swollen. There is no wheezing and no airway compromise. What is this reaction?

Correct answer: B. Angioedema

• A. Cellulitis is a bacterial soft tissue infection that develops over hours to days with erythema, warmth and fever — not within minutes of dam removal.
• B. Correct. ANGIOEDEMA is deep dermal/submucosal swelling from increased vascular permeability, most often an IgE-mediated allergic response — here, almost certainly to LATEX in the rubber dam. It characteristically involves the lips, periorbital tissue and tongue, is non-pitting, and is not itchy in the way urticaria is. Management: remove the allergen, give an antihistamine, monitor the airway closely, and add corticosteroids if progressive.
• C. Lip biting from residual anesthesia produces localized traumatic ulceration or hematoma, typically noticed later and confined to the bitten site rather than diffuse bilateral swelling.
• D. Anaphylaxis requires multi-system involvement — respiratory compromise, hypotension, or GI symptoms alongside the skin findings. With isolated lip swelling and no wheeze or hypotension, this is angioedema, not anaphylaxis. Monitor closely, since angioedema CAN progress.

Note: Latex allergy is a leading cause of angioedema in the dental setting. Also consider ACE inhibitors, which cause bradykinin-mediated angioedema that does NOT respond to antihistamines or epinephrine.