Anaphylaxis, Severe Allergic Reaction

General or Other | Emergency Medicine | Anaphylaxis, Severe Allergic Reaction (Disease)


Anaphylaxis, also known as anaphylactic shock, is a rare and severe type of allergic reaction that occurs in people who have developed an extreme sensitivity to a specific substance (allergen). This reaction happens quickly after the exposure, is severe, and involves the whole body. Anaphylaxis can occur in response to any allergen.

Symptoms develop rapidly, often within seconds or minutes. They may include the following: abdominal pain or cramping, abnormal (high-pitched) breathing sounds, anxiety, confusion, swollen face, lips, and tongue, difficulty breathing, difficulty swallowing, fainting, light-headedness, dizziness, hives, itchiness, nasal congestion, nausea, vomiting, palpitations, skin redness, slurred speech, wheezing.

Causes and Risk factors

Common causes include: drug allergies, food allergies, insect bites/stings. Pollens and other inhaled allergens rarely cause anaphylaxis. Some people have an anaphylactic reaction with no known cause.

People with atopic diseases such as asthma, eczema, or allergic rhinitis are at high risk of anaphylaxis from food, latex, and radiocontrast but not injectable medications or stings. Anaphylaxis is an emergency condition requiring immediate professional medical attention. Complications include: airway blockage, cardiac arrest (no effective heartbeat), respiratory arrest (no breathing) and shock.

Diagnosis and Treatment

To prevent anaphylaxis, avoiding triggers such as foods and medications that have caused an allergic reaction (even a mild one) in the past is a solution. Administration of epinephrine is the treatment of choice with antihistamines and steroids often used as adjuncts. ...