Allergy in perioperative setting

Adverse rection to local anesthetic agents is uncommon with true hypersensitivity reaction less than 1 ​% of all adverse reactions. Allergic reactions to local anesthetics are classified into type I (IgE-mediated) and type IV (allergic contact dermatitis). Skin test can be used in evaluating type I allergic reaction while patch testing helps diagnosing allergic contact dermatitis. Physicians also need keep in mind that non-allergic reactions such as toxic effect, sympathetic stimulation, psychomotor reaction, and vasovagal syncope can occur in patients receiving local anesthetics. Perioperative hypersensitivity (POH) reactions have an incidence between 1:353 and 1:18,600 procedures. True anaphylaxis is estimated to occur in 1:3500 to1:20,000 surgeries with clinical manifestations varying from mild skin rash to cardiovascular collapse. Anaphylaxis has a mortality rate of 1.4–4.8 %. Patient with perioperative anaphylaxis should be referred to allergist to identify the drug that led to reaction. Treatment of POH includes discontinuing any possible drugs, and with only skin involvement, using antihistamines, and in the presence of hypotension, tachycardia, bronchospasm, or gastrointestinal signs, based on severity treating with appropriate dose of epinephrine, and considering volume expansion and securing airway, if needed.