Search Menu
Search entire library by keyword
OR
Choose by letter to browse topics
A B C D E F G H I J K LM N O P Q R S T U V W X Y Z 0-9
(A-Z listing includes diseases, conditions, tests and procedures)
 

Anaphylaxis

What is anaphylaxis?    

Anaphylaxis, also called allergic or anaphylactic shock, is a sudden, severe and life-threatening allergic reaction that involves the whole body. The reaction is marked by constriction of the airways, leading to difficulty breathing. Swelling of the throat may block the airway in severe cases. Gastrointestinal symptoms, such as severe abdominal pain, vomiting and diarrhea, may also occur. Histamines, the substances released by the body during an allergic reaction, cause the blood vessels to expand, which in turn causes a dangerous drop in blood pressure. Fluid can leak into the lungs, causing swelling (pulmonary edema). Anaphylaxis can also cause heart rhythm disturbances. Any allergen can cause this reaction, but the most common ones are insect bites, food and drugs. 

Symptoms     

Symptoms develop suddenly and escalate in seconds:  

  • Difficulty breathing 

  • Confusion 

  • Rapid heart beat 

  • Swelling of the lips, tongue, throat 

  • Wheezing 

  • Slurred speech 

  • Confusion 

  • Bluish skin (cyanosis) 

  • Light-headedness, dizziness, fainting 

  • Hives and generalized itching 

  • Anxiety 

  • Heart palpitations 

  • Nausea, vomiting 

  • Diarrhea 

  • Abdominal pain or cramping 

  • Cough

Diagnosis  

As anaphylaxis is a dramatic reaction, diagnosis is relatively easy. The child will need allergy testing to determine what caused the reaction. 

Treatment    

Anaphylaxis is an emergency. Assessment of the airway, breathing and circulation should be done immediately. CPR may be needed. Children with known allergies and/or past episodes of anaphylaxis should carry an EpiPen® (epinephrine injection) that must be administered immediately. Emergency intubation, which opens the airway by placing a tube through the nose or mouth, may be needed. Another option is placing the tube into the trachea by directly cutting into the trachea. Children who have a history of allergy to insect bites/stings should be instructed to carry (and use) an emergency kit consisting of an EpiPen and should wear a MedicAlert bracelet/necklace showing their allergy. 

When to Call for Help  

If your child develops the above symptoms, call 911 or go to the nearest emergency room.

Find a physician at another Johns Hopkins Member Hospital:
Connect with a Treatment Center:
Find Additional Treatment Centers at: