Emergency medicine updates: Anaphylaxis.
Anaphylaxis is a potentially deadly condition that requires emergent therapy. While frequently treated in the emergency department (ED), recent evidence updates may improve the diagnosis and management of this condition. This paper evaluates key evidence-based updates concerning the diagnosis and management of anaphylaxis for the emergency clinician. The presentation of anaphylaxis can vary. Current diagnostic criteria can be helpful when evaluating patients for anaphylaxis, though multiple criteria exist. While the most common causes of anaphylaxis include medications, insect venom, and foods, recent literature has identified an IgE antibody response to mammalian galactose alpha-1,3-galactose, known as alpha-gal anaphylaxis. Epinephrine is the first-line therapy and is given in doses of 0.01 mg/kg (up to 0.5 mg in adults) intramuscularly (IM) in the anterolateral thigh. Intravenous (IV) epinephrine administration is recommended in patients refractory to IM epinephrine and IV fluids, or those with cardiovascular collapse. Antihistamines and glucocorticoids should not delay administration of epinephrine and do not demonstrate a significant reduction in risk of biphasic reactions. Biphasic reactions may affect 1-7% of patients with anaphylaxis. Risk factors for biphasic reaction include severe initial presentation and repeated doses of epinephrine. Disposition of patients with anaphylaxis requires consideration of several factors. Emergency clinicians must be aware of current updates in the evaluation and management of this disease.