Although babies can develop allergies to almost anything, allergies most commonly develop to foods and airborne substances that produce allergies in one or both parents. Parents and pediatricians working together can typically determine the cause of the allergy and devise strategies to protect the infant from contact with the substances that cause a reaction.
Cause
Allergies develop in babies as they do in people of all ages, as an inappropriate immune response to some substance that would not normally provoke a response. The infant's immune system reacts to this allergen by producing histamines that cause the characteristic symptoms of an allergy. According to Dr. Greene, scientists and doctors used to believe that babies couldn't develop allergies until they were about 2 years old, but in actuality even infants can develop allergies.
Types
Food allergies occur in about 4 percent of children, according to the March of Dimes, and many of these allergies develop in childhood. These can include allergies to formula--especially formula that is made from cow's milk--and in some cases may include an allergy to dairy that is passed through a mother's breast milk. Babies who have begun to eat solids most commonly react to eggs, peanuts, tree nuts, milk, soy, wheat, fish and shellfish. Some babies are allergic to allergens such as pollen, mold, dust mites or animal dander. These can cause nasal allergies that affect the respiratory system or as skin allergies that appear on the skin surface upon physical contact with the allergen.
Symptoms
Food allergies usually present as hives, itchy skin, coughing, wheezing, a red rash around the mouth or anus, diarrhea and nausea. Nasal allergies caused by airborne allergens may give a baby a runny nose, cough, red eyes and congestion. Contact allergies cause the skin to become red or swollen where the allergen touched it and may develop an itchy rash. In some cases, an allergy may cause anaphylaxis--a dangerous reaction in which the throat swells and the baby cannot breathe, blood pressure drops suddenly and the infant goes into shock. Anaphylaxis can rapidly become fatal if left untreated.
Treatment
Babies with milk allergies can sometimes be treated with antihistamines, medicines that mitigate the immune response. In the case of severe allergies, parents should get an epi pen, a special shot of adrenaline that can halt an allergic reaction, to carry at all times. All caregivers should have one of these pens and carry it whenever they are caring for the allergic infant. Some babies eventually outgrow their allergies. This often happens with allergies to cow's milk, eggs, soy and wheat, but rarely with allergies to nuts, fish or shellfish, according to the March of Dimes.
Prevention
Prevention of baby allergies involves keeping the baby's environment free of allergens. This can include using indoor air filters and filtered vacuum cleaners, avoiding foods that cause allergies, eliminating mold and dust in the home or removing pets from the home. Avoiding certain foods during pregnancy or breastfeeding has not been shown to prevent future allergies.
