Should Your Child See a Doctor?
Is this your child's symptom?
- An itchy rash made up of raised pink bumps with pale centers
- 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 frequently.
- 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 suddenly
- Trouble swallowing, drooling or slurred speech start suddenly
- You think your child has a life-threatening emergency
Call Doctor Now or Go to ER
- 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 under 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
Call 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 is present
- You think your child needs to be seen, but the problem is not urgent
Call 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 and the cause is not clear
- Hives last more than 1 week
- You have other questions or concerns
Self Care at Home
- Hives with no complications
Seattle Children’s Urgent Care Locations
If your child’s illness or injury is life-threating, call 911.
Care Advice for Hives
- 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
- 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.
- 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.
- Benadryl for Hives All Over the Body:
- Give Benadryl 4 times per day for hives all over that itch. No prescription is needed.
- If you only have another allergy medicine at home but not Benadryl, use that.
- Continue the Benadryl 4 times per day until the hives are gone for 12 hours.
- Caution: Do not use if age is under 1 year. Reason: Benadryl is a sedative. Give your doctor a call for advice.
- 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.
- 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.
- Wash Allergens Off Body:
- Give a bath or shower if caused by pollens or animal contact.
- Change clothes.
- 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.
- 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.
- 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.
- 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 information is not intended to be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.
Last Reviewed: 09/01/2012
Last Revised: 09/01/2012
Copyright 1994-2015 Barton D. Schmitt, MD. All rights reserved.