What causes allergies?
Every human body carries an arsenal of chemicals to fight off bacteria, viruses, and other intruders, but sometimes these weapons backfire. If your child has allergies, she responds to things in the environment that are not invaders. The body produces antibodies, and when your child is exposed to the irritant a second time, her body releases a number of chemicals. One of these chemicals -- histamines -- assaults not only dangerous invaders but harmless ones such as mold, pollen, food, and dander (tiny flakes of skin from pets). Rather than protecting the body, the histamine may cause sneezing fits, a runny or itchy nose, red watery eyes, and a scratchy throat.
These classic symptoms may appear very early in life, but typically first show up in children around the time they reach preschool or first grade. In addition to an itchy, runny nose, younger children and infants with allergies often develop eczema, an itchy, scaly skin rash that may flare up when they are exposed to an allergen (a substance that triggers allergies).
Some reactions are much more serious than others. Allergies to foods (such as peanuts) or insect bites (such as bee stings ) can even be deadly. If your child has such an allergy, you need to keep an autoinjector (Epi-Pen) kit containing a syringe and the drug epinephrine (adrenaline) available at all times. Seasonal allergies such as "hay fever" and other allergies caused by particles in the air are much more common and rarely life-threatening.
Why is my child allergic?
Nobody knows exactly why some children develop allergies while others don't, but the problem definitely runs in families. If you or your spouse gets watery eyes around cats or sneezes many times a day during pollen season, there's a good chance your child will, too. Yet even if neither of you suffers from allergies, you can pass along genes that make your child especially sensitive to her environment.
How can I find out what's causing my child's allergies?
If your child has a serious reaction to a food or medicine, the source of the misery will probably be obvious. But determining the cause of mild allergies can take some sleuthing. If your child's symptoms occur only in spring and fall, she's probably sensitive to pollen from trees, grass, or weeds. (If she's allergic in the early spring, the source of her discomfort is probably trees; if her symptoms occur in the late spring, she's likely sensitive to grass; and if she's sneezing and rubbing her eyes in the fall, she probably has a weed allergy.) If the problem lasts all year long, the culprit likely lurks in your house.
Dust mites on a mattress, cat or dog dander on carpets, and mold in a damp basement are all common triggers. Mild allergies to foods such as milk and wheat may also cause symptoms like those of hay fever -- but you'll notice the reaction isn't limited to warmer months. Keep in mind that allergies often take time to develop. Don't assume your Persian cat is innocent just because he's been around a lot longer than the allergy.
An allergy specialist can help you solve the puzzle by giving your child a series of skin tests. By injecting tiny extracts of allergens such as pollen and dander into her skin, the doctor can usually learn what sets off your child's immune system. Since this process can be painful, it's a good idea to see if removing possible allergen sources like pets or dusty carpets will take care of the problem before resorting to tests.
How can my child find relief?
The best way to beat allergies is to avoid the triggers - that is, by so-called "environmental control." (Your allergist can help diagnose the problem, suggest medication to control the environmental triggers, and, if necessary, prescribe immunotherapy, or allergy shots. Be aware, though, that your child may have to have weekly shots for several months, and the shots aren't always effective.) If your child is allergic to pets, consult your allergist for advice. Meanwhile, keep the pets outside or at least out of her room; washing your pet regularly also helps. For allergies to pollen, dust, and other airborne irritants, try clearing the air by keeping the windows closed, installing special filters on your air-conditioning system, and vacuuming regularly.
You should also remove any major dust collectors from your child's room, including plants, stuffed animals, and rugs or carpeting (wooden floors are best). Guard against reactions to dust mites by fitting your child's mattress and pillowcase with airtight plastic or polyurethane covers (the pillowcase goes over the plastic cover) and by washing her sheets and blankets in hot water (over 130 degrees Fahrenheit) every two weeks. (Be sure to turn the temperature back down to 120 degrees when you're through, though, to protect your child from scalding burns.)
When allergens are unavoidable, medications can bring quick relief. Over-the-counter antihistamines ease most symptoms, but they can also cause drowsiness. Two prescription allergy drugs -- cetirizine and loratadine -- have recently been approved for children as young as two. Unlike some medicines, they are very unlikely to make your child drowsy. Decongestants (such as pseudoephedrine) can clear up stuffy noses, but they also make some children irritable. Your pediatrician or an allergy specialist can help you decide which medications are right for your child.
If your child has severe reactions to a single allergen such as bee venom, a doctor might recommend a series of allergy shots that contain small amounts of the troublemaking substance. After enough injections, her immune system may eventually stop overreacting to the agent. Unfortunately, shots don't work for food allergies.
Will the allergies ever go away?
Children usually outgrow food allergies, especially if the offending item is removed from their diet for a few years. Hay fever and other respiratory allergies often subside or even disappear when a child reaches her teens, but they can come roaring back in adulthood. Of course, the symptoms of any allergy will disappear if you can clear the allergen out of daily life. If there's a bright side to the childhood trauma of losing a pet or moving to a new area, it's that your child's sneezing days may be over.
Penelope Leach, Your Growing Child. Random House:1986 90-95.
American Academy of Pediatrics, HealthyChildren.org. Allergies & Asthma. http://www.healthychildren.org/English/health-issues/conditions/allergies-asthma/Pages/default.aspx