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Medical Author:

Jerry R. Balentine, DO, FACEP

Jerry R. Balentine, DO, FACEP

Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• Anaphylaxis facts
• Introduction to anaphylaxis
• What is the history of anaphylaxis?
• How common is anaphylaxis?
• What are common causes of anaphylaxis?
• What are the signs and symptoms of anaphylaxis?
• What happens after the symptoms begin?
• Are there any disorders that appear similar to anaphylaxis?
• How is anaphylaxis diagnosed?
• How do we manage anaphylaxis?
• What are emergency measures used in the treatment of anaphylaxis?
• Can anaphylaxis be prevented?
• Patient Comments: Anaphylaxis - Causes
• Patient Comments: Anaphylaxis - Diagnosis
• Patient Comments: Anaphylaxis - Symptoms and Signs
• Patient Comments: Anaphylaxis - Describe Your Experience
• Find a local Doctor in your town
• Anaphylaxis Index

Anaphylaxis is a severe reaction that affects multiple areas of the body.

• The severity of the reaction varies from person to person.
• Subsequent reactions to the same trigger are typically similar in nature.
• The more rapid the onset of symptoms, the more severe the reaction is likely to be.
• A history of allergic disease (rhinitis, eczema, asthma) does not increase the risk of developing IgE mediated anaphylaxis, but it does incline the person to a non-IgE-mediated reaction.
• Underlying asthma may result in a more severe reaction and can be more difficult to treat.
• The risk of anaphylaxis may diminish over time if there are no repeated exposures or reactions. However, a person at risk should always expect the worst and be prepared.

The symptoms of an anaphylactic reaction may occur within seconds of exposure or be delayed 15 to 30 minutes, or even an hour or more after exposure (typical of reactions to aspirin and similar drugs). Early symptoms are often related to the skin and include

• flushing (warmth and redness of the skin),
• itching (often in the groin or armpits),
• hives.

These symptoms are often accompanied by

• a feeling of "impending doom,"
• anxiety,
• sometimes a rapid, irregular pulse.

Frequently following the above symptoms, throat and tongue swelling results in hoarseness, difficulty swallowing, and difficulty breathing.

Symptoms of rhinitis (hay fever) or asthma may occur, causing

• a runny nose;
• sneezing, and wheezing, which may worsen the breathing difficulty;
• vomiting, diarrhea, and stomach cramps may develop.

About 25% of the time, the mediators flooding the bloodstream cause a generalized opening of capillaries (tiny blood vessels) which results in

• a drop in blood pressure,
• lightheadedness,
• even loss of consciousness.

These are the typical features of anaphylactic shock.