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(A-Z listing includes diseases, conditions, tests and procedures)


What is urticaria?

Hives (urticaria) are a reaction that causes red, itchy, swollen welts on the skin. Typically, hives develop as an allergic reaction to food, drugs or other substances. Also, urticaria can occur during viral infections. Stress and sun exposure can be triggers as well. They come suddenly and go away just as suddenly.


Red itchy welts anywhere in the body that come and go suddenly are urticaria. In rare cases, hives are part of a severe allergic reaction, called anaphylaxis. Signs of anaphylaxis include:

  • 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

Anaphylaxis is an emergency. Call 911 or go to the nearest emergency room if you suspect anaphylaxis.


Avoiding any known causes and triggers of urticaria is the best way to prevent them. If the hives are caused by an allergy, antihistamines — medications that counter the immune system’s chemicals released against the allergen — may be given.

When to Call for Help

If your child develops the any of the above symptoms, call your pediatrician.

Find a physician at another Johns Hopkins Member Hospital:
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