Food allergies can be scary, and lots of parents worry about what to look for and when to be concerned. The good news is that fewer than 3 in 100 people have true food allergies, and it is even less common during infancy. A family history of food allergies, eczema or asthma may put a baby at increased risk for developing food allergies.
Allergy vs. Intolerance
True food allergies occur minutes to hours after ingestion. The most common reaction is a skin rash, but babies may develop other symptoms that range from mild to severe. Less serious reactions include hives, flushed skin, vomiting, diarrhea, and coughing or wheezing. More severe reactions include swelling of the face, lips or tongue and difficulty breathing, which can lead to loss of consciousness.
Food intolerance is more common, and usually less severe. It often involves a baby’s gastrointestinal system and causes abdominal discomfort, vomiting or diarrhea. While these symptoms are concerning and should be addressed, they generally won’t cause serious harm.
Common Food Allergies
Food allergies often appear after a baby begins to consume solid foods. Common causes of food allergies are cow’s milk, eggs, soy, peanuts, tree nuts, wheat and shellfish. Many children will outgrow allergies to cow’s milk, eggs, soy and wheat, although the other culprits usually persist into adulthood. Babies with a diagnosis of eczema or asthma are more likely to have other allergies.
Preventing Milk Allergies
Breastfeeding is the best way to prevent an allergy to milk. Several medical organizations recommend exclusive breastfeeding for six months, with continued breastfeeding until a child’s first birthday.
A small number of babies are allergic to the protein in cow’s milk and have a reaction to formula. If a true cow’s milk allergy is suspected in a formula-fed baby, your healthcare provider will likely recommend a change in formula. This could be a soy-based formula or one that is extensively hydrolyzed (hypoallergenic) so that the milk proteins are broken down and, therefore, less likely to trigger an allergic reaction.
Although rare, a breastfed infant can have an allergic reaction to cow’s milk consumed by a lactating mother. The milk protein in cow’s milk can cross into breast milk, so if you are breastfeeding, and your baby is allergic to cow’s milk, it’s important to avoid dairy products and to read food labels carefully.
The American Academy of Pediatrics recommends that parents begin to introduce solids at about six months of age. Start slowly, asking a new food no more often than every four to seven days. That way, if your baby has a reaction, you will be more likely to have an idea which food may have caused the problem.
Traditionally, cereals have been introduced first. However, it turns out there isn’t medical evidence for which foods to start first.
There is no reason to delay foods that are highly allergenic, as early feeding may decrease the risk for allergies later in life. There are exceptions, of course. Breast milk or formula should be continued until after a child’s first birthday, avoiding cow’s milk. Postpone honey until one to two years of age, due to the risk of infant botulism (not an allergy, but a serious infection).
What You Need to Know About Peanut Allergies
Peanut allergies can be especially severe. They are the leading cause of food-allergy-related death in the United States. Because of this, conventional wisdom led to recommendations to avoid peanuts, especially if someone in the family had a known peanut allergy.
Recently, we have learned that avoiding peanuts seems to increase the risk of a peanut allergy later in childhood. The new recommendations are that babies with severe eczema or an egg allergy be tested for a peanut allergy before exposure. Parents of babies with mild to moderate eczema or an egg allergy, peanut products should be introduced based on your family’s preference.
Avoiding Food Allergies
The most important way to eliminate a food allergy is to avoid the food causing the problem. Learn to read food labels, and to avoid products that contain known allergens. Processed foods often contain allergens, so home-cooked meals are best. Be alert to ingredients in restaurant food, and food served in the homes of your friends and relatives.
When to Seek Medical Attention
If you notice mild symptoms such as hives or a rash, contact your baby’s provider for further evaluation. While an initial reaction may be mild, repeated exposures can be worse.
For less severe reactions, antihistamines may be sufficient, although your provider may consider allergy testing.
Call 911 immediately if your baby is having facial swelling of the lips or tongue, is having difficulty breathing or is wheezing. This might be a sign of anaphylaxis, which is severe allergic reactions may require that you obtain a prescribed epinephrine auto-injector to keep with you at all times.
Suzanne Harrison, MD, FAAFP, FAMWA, is Director of Clinical Programs and Professor of Family Medicine and Rural Health at Florida State University College of Medicine, Tallahassee.
Meghan McCallister, MS, is a second-year medical student at Florida State University College of Medicine.