Anaphylaxis

Abstract

Anaphylaxis is a severe and often life-threatening allergic reaction mediated by mast cell degranulation in response to a variety of mediators. Early recognition and treatment are essential to reducing morbidity and mortality in patients. Anaphylaxis can have a multitude of presentations, but skin is the most common organ involved in anaphylaxis. However, the absence of cutaneous symptoms does not exclude a diagnosis of anaphylaxis, in fact, it is an independent risk factor for fatal anaphylaxis. Reduced blood pressure for age after exposure to a known allergen can be the only sign of anaphylaxis in some patients. Anaphylaxis is a clinical diagnosis but certain laboratory test, like serum tryptase, can be a helpful diagnostic tool. Many other illnesses like mastocytosis or serotonin syndrome can have similar or even near-identical presentations to anaphylaxis but can be differentiated by laboratory evaluation and a through history and physical exam. Epinephrine is the single most important therapy for the treatment of anaphylaxis. Delayed administration of epinephrine has been associated with fatal anaphylaxis and higher morbidity in patients of all ages. While medications like antihistamines and bronchodilators can help to alleviate some of the symptoms of anaphylaxis like pruritis and mild wheezing, they do not have the same degree of systemic efficacy as prompt administration of epinephrine.