An asthmatic patient develops acute wheezing and lip swelling immediately after a rubber dam is placed. The patient has no previous allergy history documented. What is the first-line treatment?

The simultaneous occurrence of wheezing (bronchospasm) and angioedema (lip swelling) immediately after rubber dam placement indicates anaphylaxis, most likely due to latex allergy. Anaphylaxis is a life-threatening emergency in which epinephrine is the first-line and only definitive treatment. Epinephrine (1:1000, 0.3-0.5 mg IM, ideally in the anterolateral thigh) rapidly reverses bronchospasm, vasodilation, and angioedema. Treatment sequence: Remove the allergen (rubber dam), administer epinephrine, call 911, then administer diphenhydramine and corticosteroids as adjuncts. Albuterol addresses bronchospasm only, not the systemic anaphylaxis. Diphenhydramine is adjunctive therapy but too slow-acting to reverse anaphylaxis. Delaying treatment is dangerous.