Hives

What Causes Those Angry Red Bumps?

By Katherine Bontrager

Hives are a reaction of immune cells, called mast cells, which sit in one's skin, Dr. Maitland says. "Mast cells act as another line of defense against germs and irritants, once the skin barrier is broken," she says. "However, various triggers that aren't necessarily dangerous can activate these cells. Common culprits include infections, especially viral infections; insect stings; airborne allergens, such as coming into contact with pollen or animal dander; certain medications, such as pain/fever medications and antibiotics; and foods."

Dr. Maitland finds that in young children certain foods can directly activate mast cells, such as strawberries, more so than in older children or adults. "Egg, milk, nuts and shellfish are also common food triggers of acute episode of hives," she says. "Lastly, there are also physical triggers or causes. For example, some individuals are 'allergic' to the cold, when exposed skin is exposed to cold temperatures and upon re-warming of the skin, hives appear. This is seen when one plunges into a cold swimming pool, then re-emerges in the warm summer sun."

Typically, hives are best treated when you remove the culprit, says Dr. Gwenn Schurgin O'Keeffe, a pediatrician in practice in Massachusetts and founder of www.pediatricsnow.com. "If the hives are due to antibiotics, you need to remove children from the medicine," she says. "Or if it's a food that's causing the outbreak, that item needs to be removed from a child's diet. But sometimes the cause is idiopathic – we just don't know if it's something in the environment or a little virus. At first, we usually have absolutely no idea what causes the reaction, which comes and goes for a couple of weeks."

Dr. Maitland agrees. "If the trigger can be identified, the best course of action is to avoid or eliminate that factor," she says. "In regards to suspected foods, it is safe for the parent or primary caregiver to remove nuts, shellfish, egg, milk, soy or fish from the diet for a few days. With medications, please contact the physician who provided the medication before stopping the antibiotic to ensure proper treatment of the pre-existing condition. Lastly, if the parent suspects allergens like pollen or animal dander, remove the clothes and then bathe with lukewarm water."

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