immunology allergic disorders
Anaphylaxis
Treatment of Anaphylaxis
Epinephrinegiven immediately Sometimes intubation IV fluids and sometimes vasopressors for persistent hypotension Antihistamines Inhaled beta-agonists for bronchoconstriction Anaphylactoid reactions are treated similarly to anaphylactic reactions. Epinephrineis the cornerstone of treatment for anaphylaxis; it may help relieve all symptoms and signs and should be given immediately. Epinephrinecan be given subcutaneously or IM (usual dose is 0.3 to 0.5 mL of a 1:1000 [0.1%] solution in adults or 0.01 mL/kg in children, repeated every 5 to 15 minutes). Maximal absorption occurs when the drug is given IM in the anterolateral (mid-outer) aspect of the thigh. Treatment is as per standard protocols. Patients with hypotension or severe airway obstruction may be given ( Treatment references , Patients who have stridor and wheezing unresponsive toepinephrineshould be given oxygen and be intubated. Early intubation is recommended because waiting for a response toepinephrinemay allow upper airway edema to progress sufficiently to prevent endotracheal intubation and require cricothyrotomy. Hypotension often resolves afterepinephrineis given. Persistent hypotension can usually be treated with 1 to 2 L (20 to 40 mL/kg in children) of isotonic IV fluids (eg, 0.9% saline). Hypotension refractory to fluids and IVepinephrinemay require vasopressors (eg,dopamine5 mcg/kg/minute). Antihistamines—both H1 blockers (eg,diphenhydramine50 to 100 mg IV) and H2 blockers (eg,cimetidine300 mg IV)—should be given every 6 hours until symptoms resolve. Inhaled beta-agonists are useful for managing bronchoconstriction that persists after treatment withepinephrine;albuterol5 to 10 mg by continuous nebulization can be given. Corticosteroids have no proven role but may help prevent a late-phase reaction;methylprednisolone125 mg IV initially is adequate. 1.White JL, Greger KC, Lee S, et al: Patients taking β-Blockers do not require increased doses ofepinephrinefor anaphylaxis.J Allergy Clin Immunol Pract6 (5):1553–1558.e1, 2018. doi: 10.1016/j.jaip.2017.12.020 2.Sturm GJ, Herzog SA, Aberer W, et al: β-blockers and ACE inhibitors are not a risk factor for severe systemic sting reactions and adverse events during venom immunotherapy.Allergy76 (7):2166–2176, 2021. doi: 10.1111/all.14785 3.Tejedor-Alonso MA, Farias-Aquino E, Elia Pérez-Fernández E, et al: Relationship between anaphylaxis and use of beta-blockers and angiotensin-converting enzyme inhibitors: A systematic review and meta-analysis of observational studies.J Allergy Clin Immunol Pract7 (3):879–897.e5, 2019. doi: 10.1016/j.jaip.2018.10.042 