Urticaria (Hives)

What are hives?

Hives (urticaria) are a sudden outbreak of red, itchy, and swollen areas on the skin. Hives can happen alone or as part of a severe allergic reaction. This condition often happens as an allergic reaction from eating certain foods or taking certain medicines. It can also be caused by many other kinds of allergens. An allergen is a substance that sets off an immune system response that leads to an allergic reaction. Common allergens include:

• Pollen
• Mold
• Mildew
• Animal dander
• Dust mites
• Cockroach droppings
• Certain foods
• Certain medicines
• Natural rubber latex
• Stinging insects like bees, wasps, or hornets

However, in many cases, the cause of the hives is not known. Hives aren't contagious. Hives can vary in size from one-half inch to several inches in size. Hives can show up all over the body or just on 1 part of the body. Mild symptoms often go away after several days by using antihistamines or steroids. But a child with a severe allergic reaction needs medical attention right away.

What causes hives in a child?

Causes of hives in children can include food, medicines, and other triggers. Common causes include:   

• Foods, such as peanuts, milk, eggs, or shellfish
• Antibiotics, such as penicillin or sulfa-containing antibiotics
• Anticonvulsant (antiseizure) medicines, such as phenobarbital
• Aspirin
• Response to an infection, commonly a virus
• Bites or stings from bees or other insects

Other types of hives include:

• Dermatographism. These hives are caused by scratching the skin, constant stroking of the skin, or wearing tight-fitting clothes that rub the skin.
• Cold-induced hives. These hives are caused by exposure to cold air or water.
• Exercise-induced urticaria. These allergic hives occur because of physical activity.
• Solar hives. These hives are caused by exposure to sunlight or light bulb light.
• Chronic idiopathic hives. These are hives that come back with no known cause. This is a very common cause of hives.

Which children are at risk for hives?

Anyone can get hives. But children with allergies are at a greater risk.

What are the symptoms of hives in a child?

These are the most common signs of hives in children:

• Itchy, pink, or red swollen areas on the skin
• Hives can appear alone, in a group, or over a large part of the body
• Hives tend to go away within 24 hours in 1 spot but come back in another spot

How is hives diagnosed in a child?

Hives can be diagnosed by your child’s healthcare provider. Your child will first complete a full health history and physical exam.

How is hives treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

The best treatment is for your child to stay away from known triggers. If the hives were caused by a medicine, your child should strictly stay away from that medicine.

Your child’s healthcare provider may also prescribe:

• Antihistamines, such as diphenhydramine or hydroxyzine (these may cause drowsiness)
• Other antihistamines that won’t make your child drowsy, such as cetirizine or loratadine

If your child is having trouble breathing, call 911 right away. Your child may get medicine called epinephrine. This medicine helps decrease the symptoms of a severe allergic reaction (anaphylaxis).

With severe allergic reactions, your child may need a second dose of epinephrine. Always keep epinephrine with your child in case of future episodes. Your child’s healthcare provider may show you how to use an emergency kit that has epinephrine. Discuss this with your child’s provider.

When should I call my child’s healthcare provider?

If your child’s symptoms get worse or they have new symptoms, talk with your child’s healthcare provider.

Follow up with your child's healthcare provider, or as advised. If your child has a severe reaction, or if your child has had several mild to medium allergic reactions in the past, ask your child's healthcare provider about allergy testing. This can help you find out what your child is allergic to.

Key points about hives in children

• Hives is a problem in which red, itchy, and swollen areas show up on the skin.
• Causes of hives include food, medicines, and other triggers.
• Treatment includes antihistamines and epinephrine, if your child has symptoms of anaphylaxis.
• Staying away from known triggers of hives is important.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.
• Before your visit, write down questions you want answered.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new directions your provider gives you for your child.
• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
• Ask if your child’s condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if your child does not take the medicine or have the test or procedure.
• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your child’s healthcare provider after office hours. This is important if your child becomes ill and you have questions or need advice.