The immune system normally functions to help the body get rid of harmful invaders, such as bacteria and viruses. In a child with allergies, the immune system overreacts to normally harmless substances such as food or pollen and treats them as it would other harmful invaders. The body releases specialized proteins and chemicals that trigger allergic reactions in the skin, eyes, throat, lungs or digestive tract. The next time a child comes into contact with the same substance that caused an initial reaction, the immune system reacts the same way.
Food
Food allergies affect an increasing number of children every year, reports the American Academy of Allergy Asthma & Immunology (AAAAI). Cow's milk, hen's egg, peanuts and tree nuts are the most common causes of childhood food allergies, followed by seafood, soy, fish and wheat. Most allergic children outgrow allergies to cow's milk, eggs and wheat by 6 years old. However, most children with allergies to peanuts, nuts or seafood may carry their allergies into adulthood, especially if they experienced severe allergic reactions in their first years of life, the AAAAI says. Allergic reactions may range from mild to life-threatening, with peanuts and nuts causing the most severe reactions.
Indoor Allergens
Indoor allergens are common causes of allergies for young children because most of their early years are spent indoors. The most common indoor allergens are molds, house dust mites and environmental tobacco smoke, according to a study on the prevention of allergic disease in childhood from the June 2004 issue of Pediatric Allergy and Immunology. The study also found that children who lived in homes with high levels of molds and house dust mites early in childhood are more likely to have severe allergies later in life. Exposure of children to tobacco smoke, specifically a mother's smoking habits, may lead to allergic rhinitis and asthma. According to this study, having more pets in the home protected the children from having asthma.
Seasonal Allergens
Pollen and outdoor molds are common causes of seasonal allergic rhinitis in children. Seasonal allergies usually develop after age 10 and reach their peaks in early adulthood, the Nemours Foundation says. Children may have seasonal allergies if they show similar allergic symptoms at the same time every year, or have symptoms that disappear after one or two seasons. Specific causes of seasonal allergies are tree pollen in the spring, grass pollen in the summer, ragweed pollen in the fall and outdoor molds during warmer seasons.
Latex
Latex is made from the sap of a Brazilian rubber tree that's used to manufacture many consumer products such as latex gloves, balloons, toys, baby bottle nipples and surgical masks, gloves and pressure cuffs. Latex allergy in children is rare, but it's becoming common in a group of high-risk children, according to the Asthma and Allergy Foundation of America. Children who are at highest risk for latex allergy include those who have a genetic spinal condition called spina bifida, and those who undergo frequent and repeated medical treatments or surgeries.
References
- American Academy of Allergy, Asthma and Immunology: Food Allergy Practice Parameter
- the "Pediatric Allergy and Immunology"; Prevention of allergic disease in childhood: clinical and epidemiological aspects of primary and secondary allergy prevention; Halken; June 2004.
- Nemours Foundation/KidsHealth.Org: Seasonal Allergies
- Asthma and Allergy Foundation of America: Latex Allergy
