Hives and Skin Allergies in Kids

An itchy rash that pops up out of nowhere can send any parent searching for answers. Two of the most common allergy-related rashes in children are hives and contact dermatitis. Both are usually mild and settle with simple care. Rarely, hives are part of a serious allergic reaction that needs emergency help right away. This guide explains how to tell these rashes apart, what usually causes them, how to soothe your child at home, and which signs mean you should call 911.

What hives look like

Hives (the medical term is urticaria) are raised, puffy welts on the skin. They can be red, pink or close to your child's skin color, and they range from tiny bumps to large patches that join together. They are usually very itchy.

One of the most telling features of hives is that they move. A single welt usually fades within hours, while new ones appear somewhere else. If you press on a hive, it often turns pale in the center. An outbreak can last from a few hours to several days. Hives that keep coming back for more than six weeks are called chronic hives and need a closer look with your pediatrician.

Common causes of hives in children

Hives happen when the body releases histamine and other chemicals into the skin. Many things can set this off:

• Viral infections. In young children, a cold or other virus is one of the most common triggers. The hives may appear during the illness or a few days after.
• Foods, such as peanuts, tree nuts, eggs, milk, shellfish, fish, sesame and others. Food-related hives usually show up within minutes to a couple of hours of eating.
• Medicines, including some antibiotics and pain relievers. Tell your pediatrician if hives start after a new medicine.
• Insect stings and bites.
• Physical triggers like heat, cold water, pressure from tight clothing, sun, sweating or exercise.
• Contact with plants, animals or latex.

In many children, no clear cause is ever found. That is frustrating, but it is also common and usually not a sign of a serious problem.

Contact dermatitis: a different kind of rash

Contact dermatitis is a rash caused by something touching the skin. Instead of moving around like hives, it stays in the area that had contact. There are two main types.

Irritant contact dermatitis

This happens when something irritates the skin directly. Common examples include harsh soaps, bubble bath, saliva around the mouth from drooling or lip licking, and wet diapers. The skin may look red, dry, chapped or sore.

Allergic contact dermatitis

This is an immune reaction to something the skin has become sensitive to. It often appears a day or two after contact and can be very itchy, with redness, bumps or small blisters. Common triggers include:

• Poison ivy, which grows in many parts of Texas, including along trails and creeks
• Nickel in jewelry, belt buckles, snaps and jean buttons
• Fragrances and preservatives in lotions, wipes and shampoos
• Some ingredients in first aid creams
• Adhesives in bandages

The shape of the rash is often a clue: a line of blisters where a plant brushed the leg, or a patch right under a belly button snap.

Home care for hives and contact rashes

• Avoid the trigger once you know or suspect what it is.
• Cool the skin. Cool compresses or a lukewarm bath can calm itching. Hot water and heat can make hives worse.
• Dress your child in loose, soft cotton clothing.
• Use gentle, fragrance-free soaps and moisturizers.
• Keep nails short to limit damage from scratching.
• After poison ivy contact, wash the skin with soap and water as soon as you can. Also wash clothes, shoes, gear and pets that may carry the plant oil.
• Ask about medicines. An oral antihistamine can ease itching from hives, and a mild hydrocortisone cream may help a small patch of contact dermatitis. Some antihistamines cause drowsiness and are not right for every age. Ask your pediatrician or pharmacist which one to use and the right dose for your child's weight.

For more detail, see MedlinePlus on hives and MedlinePlus on contact dermatitis.

When hives are an emergency: anaphylaxis

Sometimes hives are one part of anaphylaxis, a severe allergic reaction that affects more than the skin and can become life-threatening within minutes. Call 911 right away if hives or a possible allergic reaction come with any of these:

• Swelling of the lips, tongue, face or throat
• Trouble breathing, wheezing, repeated coughing or a tight throat
• A hoarse voice or trouble swallowing
• Repeated vomiting or severe belly pain after eating or a sting
• Pale or bluish skin, dizziness, fainting or floppiness
• A sense that something is very wrong

If your child has an epinephrine auto-injector, use it right away as your child's doctor instructed, then call 911. Antihistamines do not stop anaphylaxis and should never be used in place of epinephrine. Learn more on MedlinePlus's anaphylaxis page.

When to call us

Call your A thru Z Pediatrics office if:

• Hives last more than a few days, or keep coming back
• Hives appeared after a new medicine. Call before giving the next dose.
• Your child has hives along with fever, joint pain or swelling
• Welts look like bruises or leave marks after they fade
• A rash is spreading, blistering, oozing, crusting or looks infected
• Poison ivy is on the face, eyes or genitals, or covers a large area
• Your child had hives soon after eating a food, so you can discuss allergy testing and an emergency plan

Call 911 or go to the nearest ER for any sign of anaphylaxis listed above, or if your child has a rash of small purple or red spots that do not fade when pressed, especially with fever or if your child seems ill.

To have a rash checked, you can request a visit online.