Parents often don't realize that symptoms such as runny nose, rash, upset stomach, or crankiness can signal an allergy. Instead they chalk these things up to a chronic cold, infant acne, delicate stomach, or just a fussy baby. Most of the time these symptoms -- especially if they're short-lived -- are the result of a cold or another passing ailment. However, in some cases the cause is allergies.
When baby has an allergic reaction, it's the result of an inappropriate response by his immune system. The immune system is programmed to fight off illness, but sometimes it reacts to a harmless substance, like pollen, as if it were an invading parasite, virus, or bacteria. To fight back, the immune system overproduces protective proteins called antibodies. This overproduction causes swelling and inflammation of tissues -- the nasal passages, for example. Your baby's allergic reaction can recur whenever he's exposed to whatever triggered it.
The tendency to get allergies is hereditary, but specific allergies are not. For example, if you're allergic to penicillin, your child may develop allergies although he might not be allergic to penicillin.
Can you tell the difference between a cold and an allergy? It's not easy, because the symptoms are similar on the surface. These symptoms will help you distinguish a cold from an allergy:
Upper respiratory tract: A runny nose with cloudy nasal discharge and fever is probably a cold. The symptoms should go away in a week or so. But persistent, thin, watery nasal discharge may indicate allergies.
A rare and severe allergic reaction called anaphylaxis results in rapid swelling of baby's airways. This prevents baby from breathing or swallowing. If you think this is happening to your child, call 911.
Lower respiratory tract: Coughing and wheezing (noisy breathing in which your baby makes a whistling sound) are common in infants and toddlers. Babies have small, sensitive airways in their lungs. When the airways swell up as a result of a respiratory virus, babies tend to cough or wheeze. Sometimes coughing and wheezing are the result of asthma, a lower respiratory disease that affects about 15 percent of children in the United States.
Allergic babies are prone to respiratory viruses and have trouble getting rid of coughs or colds. In response to allergens and viruses, the muscles of baby's airways haves spasms and swell, leading to a dry, hacking cough. This can progress to wheezing.
Wheezing can be dangerous in a small child because it's an indication that the child is having trouble breathing. If you think your child may be wheezing, observe whether his breathing is noisier when he breathes out or in, whether he's sucking in his chest or stomach or flaring his nostrils to breathe, and whether he seems uncomfortable. If you think your child is showing any of these symptoms, call your doctor right away.
Eyes: Conjunctivitis, or pinkeye, is a condition caused by both allergies and viruses. Its symptoms are a red eye and discharge that causes the eye to be crusted shut in the morning. Allergic conjunctivitis doesn't look very different from pinkeye that's caused by a virus, so your child's pediatrician will need to make the diagnosis.
There are, however, some things you may notice that are more specific to allergy-induced pinkeye. Babies with allergies may rub their eyes frequently (allergic eyes tend to be itchy), tear excessively, have dark circles under the eyes, and be irritable.
Skin: Newborns are prone to rashes, but most rashes (including infant acne) vanish by 2 or 3 months of age. This is the time allergic rashes tend to appear. The most common allergic rash is atopic dermatitis, or eczema, and for many babies it's the first warning sign of allergic tendencies. Eczema is a red, scaly, and sometimes oozing rash on baby's cheeks, torso, arms, and legs. In toddlers and older children, it appears as persistent dry, itchy patches of skin, usually on the neck, wrists, and ankles, and in the creases of the elbows and knees.
Contact dermatitis is an allergic rash caused by a reaction to soap, detergent, wool clothing, poison ivy, or another irritant that has touched baby's body.
The classic allergic rash -- the itchy, welt-like hive -- is relatively rare in infants, and when it does occur tends to be smaller than in older children and adults (usually less than an inch long).
Stomach: Viruses can cause vomiting, diarrhea, upset stomach, and gassiness. But these symptoms can also result from allergies -- and not just to food. Children with environmental allergies may have stomach ailments as a result of swallowed phlegm, which can irritate the stomach.
Behavior: Problems with eating, sleeping, or irritability can result from allergies. Your allergic baby will be fussy and uncomfortable. That's usually due to his chronic congestion, abdominal pain, or itchy skin, eyes, or nose.
Another clue to look for is when symptoms occur. Colds are more common in the winter, but indoor allergies (such as a dust mite allergy) may be present all year. A food allergy can manifest itself anytime from a few minutes to a few hours after the offending food is eaten. Seasonal hay fever is most common in the spring or fall, but it usually doesn't affect babies.
If your baby has been suffering from allergies, you'll want to relieve his symptoms and minimize the chances of their recurring by making changes in his environment. Usual treatments for allergies include:
There's good news for infants suffering from allergies. The Food and Drug Administration has recently approved the prescription antihistamine Zyrtec for the treatment of year-round allergies in infants as young as 6 months old. It's the first and only antihistamine -- over-the-counter or prescription -- demonstrated with clinical trials to be safe in infants this young.
Allergies usually get worse unless exposure to allergens decreases. If you can eliminate baby's exposure to whatever is causing his reaction for at least six months, his body will essentially forget about it. However, it's often difficult to identify what's causing the allergy. You should keep a careful diary of what symptoms occur and when. This may expose a specific pet, article of clothing, food, or room in your house as the culprit that's causing the allergy.
Allergy testing, either by blood or skin test, can be done on children older than 2 months, but test results are harder to interpret in children this young because their immune system is still immature. Try to minimize baby's exposure to some common allergens before resorting to testing by:
If allergies run in your family, there are measures you can take to help your child avoid allergies:
Decrease baby's exposure to common allergens by creating a hypoallergenic environment for baby:
All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.
Updated May 2010