Hives

An hour after dinner you are giving your one-year-old a bath. You notice a red and white, raised welt on her tummy. You find more on her legs. Fifteen minutes later she is practically covered in welts. What could this be? Should you rush her to the ER? Should you page your doctor?Relax and don't worry. This is probably hives.

Hives are caused by an allergic reaction within the body. Histamine is released under the skin and causes areas of swelling.

They appear as red or white, raised welts on the skin. They can appear suddenly out of nowhere, and can spread rapidly. They are most common on the chest, tummy, and back, but can also be on the extremities, and rarely on the face. A very distinct characteristic of hives is that each welt will often come and go over a period of 10 to 15 minutes or as long as a few hours. You will see some welts on the tummy, and then look again an hour later and find them gone, only to see new ones on the back. The welts can be small or very large, round or irregularly shaped, single or clustered together and over-lapping. They usually itch, but not always.

There are many possible causes of hives:

• Illness – illnesses are the most common cause of hives in children. The body can have an allergic reaction to the illness. These illnesses are usually viruses, but can be any cause. So, if your child is sick, and breaks out in hives, it is probably due to the illness. A note – don't worry about what illness might be causing the hives. If there is no fever or symptoms of any illness, then the hives probably are not due to illness. If there is a fever, but no other symptoms, then it is probably a harmless virus. Click on Fever for help on what to do.
• Foods – foods that most commonly cause hives include shellfish, nuts, berries, and fish. Think about any new foods your child might have eaten in the past 24 hours.
• Medications – any medicine can potentially cause hives. Think back through the past 24 hours. Have you given your child any medication (it doesn't have to be a new medicine)? If your child is sick, have you been using any cold medicine or new kind of pain or fever medication? If so, it may be hard to tell if the hives are from the illness or the medicine.
• External irritant – there are a variety of substances that children come into contact with each day that they can be allergic too. The list includes new soap or shampoo, new laundry detergent or fabric softener, new suntan or other lotion, new clothes, blankets, or bed sheets, and playing outside among grass and bushes. Try to think of anything new that could have come into contact with your child's skin.
• Despite all these possible causes, most of the time a parent or doctor is unable to pinpoint the definite cause of the hives. It is not necessary to determine the cause of the hives unless your child continues to have a problem with recurrent hives.

Benadryl (diphenhydramine) is an antihistamine, available over-the- counter, and is the standard treatment for hives. At the first sign of hives, give your child a dose. It is best not to wait to give Benadryl to see if the hives go away on their own because some allergic reactions can proceed rapidly. The sooner the Benadryl is given, the less severe the reaction will be. You can continue giving Benadryl every 6 hours as needed.  See packaging for dosing guidelines. For infants and toddlers, the proper dose is 1 mg for every 3 pounds. For example, an 18 pound infant would get about 6 mg.

Hives usually only last for 1 or 2 days. However, they can come and go for several weeks, even though your child is no longer exposed to the original cause.

No. Benadryl is important for the first dose. You should continue it every 6 hours for the first day or two only if the hives flare up dramatically, for example, if you see more than 5 or 10 spots. If there are only a few spots, and do not seem to bother your child, then you don't need to give Benadryl. You can use Benadryl safely on and off for several weeks if needed.

No. Hives are not serious. Most cases do not need to be evaluated by a doctor. The typical parent comment is, "his rash looks terrible but he seems fine. "If, however, your child is having trouble breathing or acting progressively sicker, seek medical attention.

No. Hives on the skin have no relation to how severe or mild the reaction might be internally. The vast majority of cases of hives have no serious internal allergic reaction.

When to go to the ER: Because this is an allergic reaction, you need to observe your child for other signs of a severe allergic reaction such as throat tightness, wheezing, breathing difficulty, extreme weakness or lightheadedness, significantly pale, or persistent vomiting. Go to the ER if these happen. When to call your doctor's office for an immediate appointment: If none of the above signs of a severe allergic reaction occur, but your child has swelling of the hands, feet, or face, or the hives are all over the body, and they don't improve within 2 hours after Benadryl, see your doctor right away. If it's the weekend or after hours, go to the ER.

The vast majority of cases of hives are not serious, and go away with little or no treatment. THERE IS NO NEED TO PAGE YOUR DOCTOR AFTER HOURS, unless you need help deciding whether or not you should go to the ER.