Allergies are sensitive reactions that occur when the body's immune system reacts in any unusual way to proteins (called allergens), particularly foods, airborne dust, animal hair and pollens. As a result the body produces naturally occurring inflammatory chemicals called IgE antibodies, resulting in a wide range of conditions such as hay fever, eczema, hives and bowel problems. The condition is also called atopy.
Allergies are common in babies and children. They usually disappear as the child grows older, but sometimes can continue into adult life.
Unlike most of the common childhood illnesses (such as measles and chickenpox), an allergy can have many symptoms, and these vary widely from child to child. Allergies are not infectious and cannot be transmitted from child to child.
How to tell if a baby has an allergy
An allergic reaction might take hours or even days to develop and can affect almost any part of the body. Symptoms may be any of the following:
Digestive system (includes stomach and intestines): nausea, vomiting and spitting up of food, colicky behaviour in the young baby (including pulling away from the breast), stomach pain, diarrhoea, poor appetite, slow weight gain.
Respiratory system (includes nose, throat and lungs): runny nose, sneezing, wheezing, asthma, recurring attacks of bronchitis or croup, persistent cough.
Skin: eczema, hives, other rashes.
Other: disturbed sleep, irritability, crying fits, headache.
Common causes of allergic reaction are foods and airborne irritants.
Foods that commonly cause allergic reactions include milk and other dairy products, eggs, peanut butter; sometimes oranges, soya beans, chocolate, tomatoes, fish and wheat.
Airborne particles linked with allergic reactions include dust mites, pollens, animal hair and moulds.
Some reactions are caused by food additives such as colourings, flavourings and preservatives. Additives are found in many prepared foods (e.g. lollies, sauces, ice-cream, cordial, soft drinks, biscuits, savoury snacks and processed meats).
The allergic reaction to dairy products, particularly cow's milk, has almost the same symptoms (stomach pain and diarrhoea) as those that occur when a baby has lactose intolerance, which is when he or she cannot digest the sugar (lactose) in dairy products. The correct diagnosis is a matter for your doctor.
Although they don't strictly cause allergic reactions, some soaps and detergents can cause a chemical irritation of the skin and aggravate some skin conditions.
Allergy cannot be inherited directly by children from their parents, but children from families whose members have allergies have a greater chance of becoming allergic themselves. However, anyone can become allergic.