Anaphylaxis ("ann-uh-fuh-LAK-suss") is a severe allergic reaction that affects the entire body (systemic). It can occur within a few seconds or minutes after a person is exposed to a substance (allergen or antigen).

Symptoms and signs of a severe allergic reaction may include:

  • Itching.
  • Raised, red bumps on the skin (hives or wheals).
  • Wheezing or difficulty breathing.
  • Rapid swelling, either in one area or over the entire body. Swelling is most serious when it involves the lips, tongue, mouth, or throat and interferes with breathing.
  • Belly pain or cramps.
  • Nausea or vomiting.
  • Low blood pressure, shock, and unconsciousness.

The sooner symptoms occur after exposure to the substance, the more severe the anaphylactic reaction is likely to be. An anaphylactic reaction may occur with the first exposure to an allergen, with every exposure, or after several exposures. An anaphylactic reaction can be life-threatening and is a medical emergency. Emergency care is always needed for an anaphylactic reaction.

How can you care for an anaphylactic reaction?

  • If your doctor has prescribed medicine, such as an antihistamine, take it exactly as directed. Call your doctor if you think you are having a problem with your medicine.
  • Learn all you can about your allergies. You may be able to avoid a severe response when you do or don’t do certain things. For instance, you can check food or drug labels for contents that might cause problems.
  • Your doctor may prescribe a shot of epinephrine to carry with you in case you have a severe reaction. Learn how to give yourself the shot. Keep it with you at all times. Make sure it has not expired.
  • Wear medical alert jewelry that lists your allergies. You can buy this at most drugstores.
  • Teach your family and friends about your allergies. Tell them what you need to avoid. Teach them what to do if you have a reaction.
  • Before you take any medicine, tell your doctor if you have had a bad response to any medicines in the past.
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Listed below are Signature Medical Group physicians who diagnose and treat this condition.

Hamsa N. Subramanian, MD

Hamsa N. Subramanian

St. Louis, MO

  • Allergy and Immunology
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Signature Allergy & Immunology

Signature Allergy & Immunology
425 North New Ballas
Suite 203
St. Louis, MO 63141
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