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Hives

What are Hives

Hives are red, raised, round or oval-shaped bumps on the skin. They are often itchy as well. Hives come from many causes, but they are most commonly part of an allergic reaction. They often appear quite suddenly, and very frequently it is hard to figure out exactly what caused them. People with very sensitive skin can get hives from no obvious source, and some people develop hives from emotional stress or anxiety, or even exposure to cold temperature. When a person has hives, cells in the middle layers of skin release chemicals that cause increased blood flow, swelling, and inflammation. This reaction is often triggered by histamine, the chemical that is the main culprit in allergic reactions. Hives may last anywhere from minutes to days, depending on their cause and on what we do about them. As they get older, hives often change color from bright pink to darker red and even dusky purple in the center. There are a few conditions we’ll discuss below in which hives can represent serious illness.

What is the biggest concern?

Although hives are usually only troublesome because of their itching, the most important immediate concern is to be sure the child is not having a more serious reaction. Severe allergic reactions called “anaphylaxis” (ann-ah-fill-axis) can progress very quickly, and produce wheezing, difficulty breathing, and even collapse of the heart and blood vessels. Once we are sure that a child is not having a severe reaction, the next concern is to try to determine what caused it. In more than 50% of children with first-time hives, we cannot find a cause. Fortunately, most children do not have recurrent episodes of hives, and if they do, the circumstances often help us figure out what caused them. The child’s most immediate concern is usually the itching, which can range from mild to nearly intolerable. There are manymedications to help with the itching.

Hives treatment

Even though we often can’t determine the exact cause of hives, we can usually tell what sort of thing triggered them. Depending on what seems to be the cause in your child’s case, you may want to read our Aftercare Instructions on Environmental Allergies, Food Allergies, orInsect Bites and Stings. Regardless of the cause of the hives, there are some things you can do to help your child feel more comfortable.

Doctors usually treat mild cases of hives with antihistamine medications. These medicines interfere with the release of the body chemicals that cause the hives. They reduce itching and prevent new hives from forming, but they don’t make existing hives go away. The oldest antihistamine in common use is diphenhydramine (dye-fen-hi-drah-meen; Benadryl® and many others). It is available as liquid or capsules that you give about every six hours. The main side effect of diphenhydramine is drowsiness, which is actually often helpful to a child whose itching is making him or her frantic and unable to sleep. Some parents prefer to use this medicine for that reason.

Many newer antihistamines are available that you can give only once or twice a day. These include loratadine (Claritin®), desloratidine (Clarinex®), and fexofenadine (Allegra®) and many others. Most of these newer drugs do not cause drowsiness. Your doctor will recommend an antihistamine that is right for your child.

In addition to medication, your child may feel more comfortable if you use cool wet compresses or cool baths to soothe the skin, unless you think it was cold air or water that caused the hives. Lotions and ointments usually do not help, and some can make the condition worse.

Your doctor will talk with you about whether your child should have allergy testing. Most children who have only one episode of hives, or who continue to have only mild episodes don’t need allergy testing or allergy shots. In more severe cases, such as if your child has wheezed or had trouble breathing, your doctor will recommend testing and possibly other measures as well. Children with very severe allergic reactions often use an “Epi-Pen®,” which is a device to give themselves a shot of adrenaline.

Dangerous Symptoms of Hives

Hives are a symptom of some kind of allergic reaction. They usually go away after a few days and some antihistamines, but sometimes the reaction can get worse, especially if we don’t know what caused it. Here are some things to look out for that suggest the allergy is getting worse, or that something else is going on:

  • Rapidly spreading hives even after medications
  • Wheezing (whistling breath sounds)
  • Difficulty breathing or speaking
  • Complaint of a feeling of swelling in the throat or tongue
  • A pale or bluish color of the lips or fingernails
  • Puffiness around the eyes
  • Fever
  • Vomiting
  • Abdominal pain
  • Change in urine color to dark brown or red
  • Blistering skin or sores in the mouth, vagina or anus or eyes
  • Joint swelling

If any of these occur, please be sure to call your doctor’s office right away. If your child seems to be having trouble breathing or speaking, go directly to the emergency room.

Other points of concern

Children occasionally scratch so hard at their hives that they break the skin. This can cause infections and (rarely) scarring. We can do our best to prevent this with antihistaminemedications, cool soaks, and distracting the child with something interesting. If the skin around a hive looks broken, red, or drains pus, please call your doctor.

Other Conditions that Might Be Present with Hives

Hives usually represent some kind of allergic reaction, but sometimes they are signs of other conditions. Here are a few uncommon but concerning conditions that can start off looking like hives:

  • Erythema multiforme (err-ah-theme-ah mul-tee-form-ee), or EM, is an unusual condition that starts off with hives that are not usually itchy. The hives often turn into target-shaped circles, with a rim of red, a clear space, and more red on the inside. Over time, the inner part of the red areas can turn dusky purple. The bumps usually appear all over the body. Drug reactions and viral infections cause some cases of EM, and in others we never find out the source. In rare cases, EM becomes more severe and can cause peeling skin, sores in the mouth and eyes, and even organ damage. Unlike children with simple hives, children with EM usually look and feel sick.
  • Henoch-Schoenlein Purpura, or HSP, is another rare condition which causes raised bumps on the skin. The bumps in HSP are usually dark red or purple, and often (but not always) on the child’s lower back, buttocks, and legs. The bumps are usually not itchy, but they may be painful. Some children with HSP develop similar bumps inside their intestines, which then cause abdominal pain or cramps. Occasionally this can cause more serious problems. About 5% of children with HSP also develop kidney problems. If your child with hives develops abdominal pain,vomiting, or changes in the urine, please call your doctor right away.
  • Lyme disease is an infection that children can get from tick bites. It is unusual, but id does happen in late spring and summer in the US. One part of Lyme disease is a red raised rash that can appear as irregular circles or curves. The rash often moves around on the body. Children with Lyme disease usually have fever and may also have headache and feel generally ill.
  • A much less severe condition called pityriasis rosea (pitt-ah-rye-ah-siss rose-ee-ah), or PR, causes bumps that look like hives in older children and teenagers. PR often starts of with a single patch of red on the chest, shoulder, or upper back. A few days later the child or teen develops very itchy flattened bumps across the entire back and/or chest. PR is harmless but uncomfortable, and it can take up to three weeks to clear.