Hives

Is this your child's symptom?

  • An itchy rash made up of raised pink bumps
  • Most often, rash is very itchy

Symptoms of Hives

  • Raised pink bumps with pale centers (welts)
  • Hives look like mosquito bites
  • Sizes of hives vary from ½ inch (12 mm) to several inches (cm) across
  • Shapes and location of hives can be different. They can also change often.
  • Itchy rash

Causes of Widespread Hives

  • Viral Infection. The most common cause of hives all over the body is viral infections. Research has confirmed this. Other symptoms such as a fever, cough or diarrhea are also present. The hives may last 3 days. This is not an allergy.
  • Bacterial Infection. Some bacterial infections can also cause hives. A common example is Strep. Hives are also seen with bladder infections. (UTIs)
  • Drug Reaction. An example is a penicillin rash. Most rashes that start while taking an antibiotic are viral rashes. Allergy tests are normal 90% of the time. Only 10% turn out to be a drug allergy.
  • Food Reaction. May be an allergy or a coincidence. If the food is a high risk one (such as peanuts), consult an allergist. Hives from foods usually resolve in 6 hours. Hives from infections last for days. Only 3% of hives are due to a food.
  • Bee Sting. Widespread hives after a sting may be part of a serious allergic reaction. Need to consult an allergist.
  • Anaphylactic Reaction (Very Serious). The sudden onset of hives with trouble breathing or swallowing. This is a severe allergic reaction to an allergic food or drug. Most often begins within 30 minutes of swallowing the substance. Always within 2 hours of exposure.
  • Unknown. Over 30% of the time, the cause of hives is not found.

Causes of Localized Hives

  • Irritants. Hives just in one spot are usually due to skin contact with an irritant. They are not an allergy.
  • Plants. Many plants cause skin reactions. Sap from evergreens can cause local hives.
  • Pollen. Playing in the grass can cause hives on exposed skin.
  • Pet Saliva. Some people get hives where a dog or cat has licked them.
  • Food. Some children get hives if a food is rubbed on the skin. An example could be a fresh fruit. Some babies get hives around their mouth from drooling a new food.
  • Insect Bite. Local hives are a reaction to the insect's saliva. Can be very large without being an allergy.
  • Bee Sting. This is a reaction to the bee's venom. Can be very large without being an allergy.
  • Localized hives are not caused by drugs, infections or swallowed foods. These get into the bloodstream and cause widespread hives.

When to Call for Hives

Call 911 Now

  • Hives and life-threatening allergic reaction to similar substance in the past and exposure less than 2 hours ago
  • Trouble breathing or wheezing
  • Hoarse voice or cough start all of a sudden
  • Trouble swallowing, drooling or slurred speech start all of a sudden
  • You think your child has a life-threatening emergency

Call Doctor or Seek Care Now

  • Hives start after eating a high-risk food. High-risk foods include nuts, fish, shellfish, or eggs.
  • Hives started after taking a prescription medicine
  • Age less than 1 year with hives all over
  • Your child looks or acts very sick
  • You think your child needs to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

  • Hives started after taking an over-the-counter medicine
  • Severe hives (such as eyes swollen shut or very itchy)
  • Fever or joint swelling is present
  • Stomach pain or vomiting
  • You think your child needs to be seen, but the problem is not urgent

Contact Doctor During Office Hours

  • Hives make it hard to go to school or do other normal activities. Note: taking Benadryl for 24 hours has not helped.
  • Food could be the cause
  • Had hives 3 or more times in past year with no known cause
  • Hives last more than 1 week
  • You have other questions or concerns

Self Care at Home

  • Hives with no other problems

Seattle Children's Urgent Care Locations

If your child’s illness or injury is life-threatening, call 911.

Care Advice for Hives

  1. Hives Only on One Part of the Body - What You Should Know:
    • Most are caused by skin contact with an irritant. Examples are plants, pollen, food or pet
      saliva.
    • Localized hives are not caused by drugs, infections or swallowed foods. They are also not an allergy.
    • Wash the allergic substance off the skin with soap and water.
    • If itchy, use a cold pack for 20 minutes. You can also rub the hives with an ice cube for 10 minutes.
    • Hives just on one part of the body should go away on their own. They don't need Benadryl.
    • They should go away in a few hours.
  2. Hives All Over the Body - What You Should Know:
    • Over 10% of children get hives 1 or more times.
    • Most widespread hives are caused by a viral infection. This is not due to an allergy. Less than 10% are an allergic reaction to a food, drug, or insect bite. Often, the cause is not found.
    • Here is some care advice that should help.
  3. Allergy Medicine for Hives All Over the Body:
    • Give Benadryl 4 times per day for hives all over that itch. Age limit: 1 and older.
    • Use an allergy medicine until the hives are gone for 12 hours.
    • If the hives last more than a few days, switch to a long-acting antihistamine, such as Zyrtec. No prescription is needed. Age limit: 2 and older.
    • Caution: if your child is less than 1 year, call your doctor for advice.
  4. Hives Caused by Foods:
    • Foods can cause widespread hives.
    • Sometimes, the hives are just around the mouth.
    • Hives from foods usually last just a short time. They often are gone in less than 6 hours.
  5. Cool Bath for Itching:
    • To help with the itching, give a cool bath. Do this for 10 minutes. Caution: Avoid causing a chill.
    • Can also rub very itchy spots with an ice cube for 10 minutes.
  6. Wash Allergens Off Body:
    • Give a bath or shower if caused by pollens or animal contact.
    • Change clothes.
  7. Stay Away from Allergens:
    • If you know what is causing the hives, avoid this substance. An example is certain foods.
    • Help your child stay away from this allergen in the future.
  8. Return to School:
    • Hives cannot be spread to others.
    • Your child can go back to school once feeling better. The hives shouldn't keep him from normal activities.
    • For hives from an infection, can go back after the fever is gone. Your child should feel well enough to join in normal activities.
  9. What to Expect:
    • Hives all over from a viral illness normally come and go.
    • They may last for 3 or 4 days. Then, they go away.
    • Most children get hives once.
  10. Call Your Doctor If:
    • Severe hives not better after 2 doses of Benadryl
    • Itch not better after 24 hours on Benadryl
    • Hives last more than 1 week
    • You think your child needs to be seen
    • Your child becomes worse

And remember, contact your doctor if your child develops any of the 'Call Your Doctor' symptoms.

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

Last Reviewed: 10/11/2023

Last Revised: 12/30/2022

Copyright 2000-2023. Schmitt Pediatric Guidelines LLC.