title: Anaphylaxis.
abstract: BACKGROUND
  Anaphylaxis is the quintessential critical illness in emergency medicine. Symptoms are rapid in onset and death can occur within minutes. Approximately 1500 patients die annually in the United States from this deadly disorder. It is imperative, therefore, that emergency care providers be able to diagnose and appropriately treat patients with anaphylaxis. Any delays in recognition or initiation of therapy can result in unnecessary increases in patient morbidity and mortality.
  
  
  CONCLUSIONS
  Recent literature, including updated international anaphylaxis guidelines, has improved our understanding and management of this critical illness. Anaphylaxis is a multisystem disorder that can manifest signs and symptoms related to the cutaneous, respiratory, cardiovascular, and gastrointestinal systems. Epinephrine remains the drug of choice and should initially be administered intramuscularly, into the anterolateral thigh, as soon as the diagnosis is suspected. For patients unresponsive to repeated intramuscular injections, a continuous infusion of epinephrine should be started. Antihistamines and corticosteroids are second-line medications and should never be given in lieu of, or prior to, epinephrine. Aggressive fluid resuscitation should also be used to treat the intravascular volume depletion characteristic of anaphylaxis. Patient observation and disposition should be individualized, as there is no well-defined period of observation after resolution of signs and symptoms.
  
  
  CONCLUSIONS
  For patients with anaphylaxis, rapid and appropriate administration of epinephrine is critical for survival. Additional therapy, such as supplemental oxygen, intravenous fluids, antihistamines, and corticosteroids should not delay the administration of epinephrine.
authors.affiliation: Department of Medicine, Division of Critical Care, Weiss Memorial Hospital, Chicago, Illinois.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Zilberstein
authors.affiliation: Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland; Division of Pulmonary and Critical Care, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.
authors.forename: Michael T
authors.initials: MT
authors.lastname: McCurdy
authors.affiliation: Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Winters
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000707:Anaphylaxis / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage; D004635:Emergency Medicine / Q000379:methods*; D004837:Epinephrine / Q000008:administration & dosage; D005440:Fluid Therapy / Q000379:methods; D006633:Histamine Antagonists / Q000627:therapeutic use; D006801:Humans; D012151:Resuscitation / Q000379:methods*; D012307:Risk Factors
chemical_list: D000305:Adrenal Cortex Hormones; D001993:Bronchodilator Agents; D006633:Histamine Antagonists; D004837:Epinephrine
keywords: allergic reaction; anaphylactic shock; anaphylaxis; antihistamines; cardiogenic shock; corticosteroids; distributive shock; epinephrine; hypovolemic shock