Health A-Z

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Symptoms of anaphylaxis usually occur within seconds to minutes of exposure to the allergen, but symptoms can be delayed for several hours. For some people, symptoms do not always show up after an exposure, but are triggered if an exposure is followed by vigorous exercise. Symptoms range from mild to very severe. These symptoms can include:

  • Rapid pulse, sweating, dizziness, fainting, unconsciousness

  • Wheezing, chest tightness, difficulty breathing, coughing

  • Itchy hives, which may blend together to form larger areas of skin swelling

  • Swelling of the lips, tongue or eyes

  • Nausea, vomiting, abdominal cramps, diarrhea

  • Paleness, bluish skin color

  • Throat swelling, with a feeling of throat tightness, a lump in the throat, hoarseness or obstructed air flow

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From Health A-Z, Harvard Health Publications. Copyright 2007 by the President and Fellows of Harvard College. All rights reserved. Written permission is required to reproduce, in any manner, in whole or in part, the material contained herein. To make a reprint request, contact Harvard Health Publications. Used with permission of StayWell.

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