Anaphylaxis

Alternative Names

Symptoms

Symptoms develop rapidly, often within seconds or minutes. They may include the following:

• Abdominal pain or cramping
• Abnormal (high-pitched) breathing sounds
• Anxiety
• Confusion
• Cough
• Diarrhea
• Difficulty breathing
• Fainting, light-headedness, dizziness
• Hives, itchiness
• Nasal congestion
• Nausea, vomiting
• Sensation of feeling the heart beat (palpitations)
• Skin redness
• Slurred speech
• Wheezing

Exams and Tests

Signs include:

• Abormal heart rhythm (arrhythmia)
• Fluid in the lungs (pulmonary edema)
• Hives
• Low blood pressure
• Mental confusion
• Rapid pulse
• Skin that is blue from lack of oxygen or pale from shock
• Swelling (angioedema) in the throat that may be severe enough to block the airway
• Swelling of the eyes or face
• Weakness
• Wheezing

The health care provider will wait to test for the specific allergen that caused anaphylaxis (if the cause is not obvious) until after treatment.

References

The diagnosis and management of anaphylaxis: an updated practice parameter. J Allergy Clin Immunol. 2005 Mar;115(3 Suppl):S483-523.

Sicherer SH, Simons FE, Section on Allergy and Immunology, American Academy of Pediatrics. Self-injectable epinephrine for first-aid management of anaphylaxis. Pediatrics. 2007;119:638-646.

Simons FE. Anaphylaxis. J Allergy Clin Immunol. 2008;121:S402-S407.

Sampson HA, Muñoz-Furlong A, Campbell RL, Adkinson NF Jr, Bock SA, Branum A, et al. Second symposium on the definition and management of anaphylaxis: summary report-second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium. Ann Emerg Med. 2006; 47:373-380.