What are hives?
Hives, also known as urticaria or welts, are swollen, often itchy areas on the skin. They can show up in different shapes and sizes, but they're usually well defined, with a pale, raised central area surrounded by a red border.
© Dr P. Marazzi / Science Source
Hives are common. They typically last for a few hours to a few days, but it's possible to have them for months at a time. They aren't contagious, but they may spread on the skin. They may disappear from one area of your child's skin only to crop up elsewhere.
What causes hives?
Hives occur when the body releases a chemical called histamine. There are so many possible reasons for hives that you may have trouble identifying the culprit. Here are the most common ones:
Insect bites and stings. If your child is allergic to bees or fire ants, for example, he could develop hives in reaction to being stung or bitten.
Food: A child might get hives in reaction to something he eats. The most likely foods are milk, eggs, peanuts, tree nuts (such as almonds, walnuts, or pecans), soybeans, wheat, fish, and shellfish. Certain food additives and preservatives can also trigger hives. A child may break out in hives because he's allergic to the protein in the food or because his body reacts to a chemical in the food by releasing histamine. Some children even develop hives simply from coming into contact with certain foods – for example, when the juice from a strawberry gets on their skin.
Allergens: If your child has an allergy to cats, for example, he may break out in hives when he touches a cat. A child may even develop hives in reaction to an allergen in the air, like pollen.
Illness: A child might get hives when he has a cold or other viral infection. These hives usually last for a week or two before disappearing. Less commonly, he may get hives when he has a bacterial infection.
Temperature: Cold temperatures sometimes cause hives. The same goes for a sudden change in temperature, such as when a child's skin warms up after being cold.
Drugs: Antibiotics and some other medications might cause a child to break out in hives.
How should I treat hives?
If you think your child has hives because of a pet or pollen allergy, give her a bath to rinse away as much of the allergen as possible. Cool compresses and cool baths sometimes provide relief. You might also try dabbing the hives with calamine lotion on a cotton ball.
Avoid dressing your child in clothing that's snug in the area where she has hives.
If hives are making your child uncomfortable, ask her doctor whether you can give her the appropriate dose of an oral antihistamine to reduce itching and swelling.
When should I call 911?
Call 911 immediately if your child has hives along with any of the following:
- respiratory symptoms, such as wheezing or shortness of breath
- swelling of the face or tongue
- difficulty swallowing
- dizziness or lightheadedness
Along with hives, these symptoms can signal anaphylactic shock, a potentially fatal allergic reaction. If your child is still a baby, keep in mind that a baby's respiratory system is so tiny that even a small amount of swelling can make it very difficult for him to breathe.
When should I call the doctor?
Call the doctor if your child is younger than 2 years old and has widespread hives (more than one location).
In addition, call the doctor if a child of any age:
- gets widespread hives after a sting or in reaction to medicine or food
- has hives and seems very ill (has a fever, lethargy, nausea, persistent vomiting or crampy abdominal pain, for example)
- has swollen hands, feet, or joints
Also talk with your child's doctor if the hives last more than a week. While most hives don't require special attention, chronic cases may call for skin testing for food or drug sensitivities, blood tests for underlying diseases, or (uncommonly) a skin biopsy.
If you've given your child an oral antihistamine (according to your doctor's advice) and she's still not comfortable, or if the antihistamine seems to make her too sleepy, call and ask the doctor about other options. Occasionally doctors will prescribe steroids, such as prednisone, to treat hives that don't respond to antihistamines.