Hives & Swelling

The itchiness, grouping and size range of hives make them different from other allergic skin reactions like atopic dermatitis. Hives may occur suddenly as a reaction to a specific trigger (acute hives), or they may occur repeatedly or for long periods of time (chronic hives).

Hives may appear with angioedema (swelling of the deeper tissue of the skin). Angioedema usually does not itch and commonly occurs around the eyes, lips, tongue, hands and feet. Children who have hives with angioedema are more likely to have recurring or chronic hives.

The symptoms of hives may last anywhere from a few minutes to a few months or longer. Signs and symptoms of hives often include:

• Itching
• Red, raised bumps or welts on the skin that turn white when pressed (blanching)
• Sudden appearance and disappearance of these bumps

Angioedema (swelling) can occur at the same time as hives or as a separate reaction. Symptoms of angioedema include:

• Swelling around the eyes or the lining of the eyes
• Swelling of the hands and/or feet
• Swelling of the mouth and/or throat
• Difficulty breathing
• Stomach cramps

Hives can appear in one area or all over the body. If your child suddenly develops severe hives or angioedema and is having trouble breathing, is vomiting or loses consciousness, he or she may be experiencing anaphylaxis, a severe allergic reaction. Anaphylaxis is an emergency. If you think your child is experiencing a severe allergic reaction, take him or her to the hospital for immediate treatment.

Many different factors can cause your child to develop hives or swelling. These causes may be physical reactions, allergic reactions or nonallergic reactions.

Physical causes include:

• Cold
• Heat
• Pressure
• Sunlight
• Vibration
• Water

Allergic reactions can cause hives or swelling in response to:

• Pollens
• Dander
• Mold spores
• Foods
• Drugs
• Insects

Nonallergic causes of hives include:

• Infections
• Idiopathic reasons (no cause is found)
• Autoimmune conditions
• Other conditions

Diagnosis of Hives & Swelling

As a first step to diagnosing the cause of hives and swelling, the allergy doctors at Riley at IU Health will ask about your child's medical history and do a physical exam. The focus will be on exposures that may be contributing to the problem.

Allery specialists will often perform an evaluation if the problem is chronic (for example, a child is has hives daily for two to three months). It can be extremely difficult to identify and confirm causes of chronic hives, but the allergy specialists at Riley at IU Health are trained to review your child's medical history to help determine a possible cause and direct any further testing.

In the case of acute hives, there may be an obvious food or substance such as peanuts or a medicine that acts as a trigger. Acute hives may not require further evaluation or allergy testing unless a food is part of the history or there is anaphylaxis.

If your child's allergist suspects a food allergy based on your child’s history, the doctor may perform a food allergy test and may suggest a food challenge to confirm the diagnosis.