Sizes of hives vary from ½ inch to several inches across
Shapes of hives are variable and change repeatedly
Itchy rash
Causes
Widespread hives usually are caused by a viral infection. Can also be an allergic reaction to a food, drug, infection, insect bite, or other substances.
Localized hives are usually due to skin contact with plants, pollen, food or pet saliva. Localized hives are not caused by drugs, infection or swallowed foods.
See More Appropriate Topic (instead of this one) If
Doesn't look like hives, see RASHES WIDESPREAD AND CAUSE UNKNOWN
It's probably mosquito bites, see INSECT BITES
(To go directly to these topics, click on the links following this document.)
WHEN TO CALL YOUR DOCTOR FOR HIVES
Call 911 Now (your child may need an ambulance)(for symptoms of anaphylaxis) If
Difficulty breathing or wheezing
Hoarseness or cough with rapid onset
Difficulty swallowing or slurred speech with rapid onset
Severe allergic reaction in the past to similar substance
Call Your Doctor Now (night or day) If
Your child looks or acts very sick
Hives began after a bee sting, unusual food or medicine and no previous reactions
Call Your Doctor Within 24 Hours (between 9am and 4pm) If
You think your child needs to be seen
Severe hives (eyes swollen shut, very itchy, etc.) not improved after 2nd dose of Benadryl
Fever, abdominal pain or joint swelling is present
Call Your Doctor During Weekday Office Hours If
You have other questions or concerns
Hives interfere with school or normal activities after taking Benadryl every 6 hours for more than 24 hours
Unexplained hives have occurred 3 or more times
Parent Care at Home If
Hives with no complications and you don't think your child needs to be seen
HOME CARE ADVICE FOR HIVES
1. Localized Hives:For localized hives, wash the allergic substance off the skin with soap and water. If itchy, massage the area with a cold washcloth or ice. Localized hives usually disappear in a few hours and don't need Benadryl.
2. Benadryl: Give Benadryl 4 times per day for widespread hives that itch. (See Dosage chart) (Note: if you only have another antihistamine at home, use that)
Contraindication: Weight < 20 pounds (Reason: Benadryl is a sedative). Give your doctor a call for advice.
Continue the Benadryl 4 times per day until the hives are gone for 12 hours.
3. Cool Bath: Give a cool bath for 10 minutes to relieve itching. (Caution: avoid any chill) Rub very itchy areas with an ice cube for 10 minutes.
4. Remove Allergens: Give a bath or shower if triggered by pollens or animal contact. Change clothes.
5. Avoid Allergens: If you identify a substance that causes hives, help your child avoid that substance in the future.
6. Contagiousness: Hives are not contagious. Your child can return to day care or school if the hives do not interfere with normal activities.
7. Expected Course: Hives normally come and go for 3 or 4 days, then disappear. Most children get hives once.
8. Call Your Doctor If
Severe hives persist after 2nd dose of Benadryl
Most of the itch is not relieved within 24 hours on continuous Benadryl
Hives last > 1 week
Your child becomes worse or develops any of the "Call Your Doctor" symptoms.
Lucile Packard Children's Hospital is located in Palo Alto, adjacent to Stanford University Hospital, approximately 20 miles north of San Jose, CA and 40 miles south of San Francisco.
