When bugs bite, babies often have bigger reaction than adults

This time of year, lots of babies comes into my office with large red bumps on their arms or legs. The parent is often worried that the baby has an infected bug bite or is developing an allergy to the bug.

The truth is, we are all somewhat allergic to insects. When we are bitten by a bug, we develop what is known as a wheal and flare reaction. The body detects a foreign substance in the inoculum (injected material from the bug) as well as the penetrating trauma to the skin. A response to such an assault starts a process that results in the blood vessels in the area dilating and fluid pouring into the tissue around the bug bite. This process is an allergic response and results in the redness, itching, and swelling following a bite. Occasionally, with some types of bugs such as bees, there is also pain. Some of this response is caused by the white blood cells sending chemicals in response to the foreign assault.

While we are all allergic to these foreign critters, how our bodies react changes with age. Babies seem to mount a more dramatic response to a simple bug bite. The wheal and flare reaction can be large. When I see a large red welt on a baby’s arm, I rarely suspect an infected bug bite — just the usual exaggerated response. Putting an ice pack or cold pack on the bite immediately after it occurs will prevent the swelling. The ice prevents the dilation of the blood vessels (cold causes the vessels to constrict) and the allergic process is halted. As the child gets older, the reactions usually are less dramatic.

Occasionally, bug bites do get infected. Infections may follow a bite if the child is adamant about itching it to death. Trimming the child’s fingernails and application of a cold pack can prevent these attacks of itching. If there is fever, pus, increased pain at the site of the bite, or red streaks coming out of the bite, the bite may be infected. You should see your child’s doctor in this case.

Some children develop a serious allergy to certain insects, usually bees. In this case, repeated exposure to the bee inoculum creates an increasingly severe response with each sting. Children with bee allergies can have a reaction so severe it results in death. If after a bee sting, the child develops hives (big raised welts all over the body), wheezing, or swelling of the tongue, he should be taken to the nearest emergency room for treatment. His physician may send him to an allergist for further testing. It is a good idea to have Benadryl on hand at home in case your child has an allergic reaction to anything. Benadryl is an antihistamine that can stop the allergic process. However, if your child has a bee allergy, you should also have an epi pen junior (or regular epi pen when your child hits 50 pounds). An epi pen is a simple pen-like injector that can be poked into the thigh muscle to allow instant opening of the airway. Usually, we give parents at least two epi pens so that the family can place one in the glove compartment of the car.

Does your child have a bee allergy? Any tips for avoiding these pesky critters?

Dr. Victoria McEvoy graduated from Harvard Medical School in 1975 and is currently an Assistant Professor of Pediatrics at HMS. She is the Medical Director and Chief of Pediatrics at Mass General West Medical Group. She has practiced pediatrics for almost thirty years. She has been married to Earl for thirty six years and raised four children. She currently enjoys writing, traveling, reading, almost all sports, and spending time with her two grandsons.

 Family Health Guide

To take advantage of the latest medical advances, and to deal with the often-confusing world of health care, you need information that is clear, accurate, easily understandable, and accessible. The Harvard Medical School Family Health Guide brings you the information you need to keep your and your family healthy and to cope with illness when it does strike. 170 faculty members of Harvard Medical School, physicians who care for patients every day, developed this comprehensive guide.

Do you have a baby? Connect with others with similar health concerns and issues. Click here to join the group.

This content is not intended to substitute for personalized medical advice, diagnosis, or treatment from your healthcare provider. Read our full disclaimer.