Allergic conditions can begin at any age. Infants can develop eczema soon after birth. Babies can also suffer from asthmatic reactions to viruses, with chronic coughs and/or wheezing following colds. Preschoolers may develop sensitivity to milk and chronic sinus congestion or ear problems. It is during the ages 5 through 10, however, that allergies and asthma become especially prevalent. Children at this age develop seasonal hay fever attacks and asthmatic reactions to animals, dust mites, and plants. Asthma may also manifest as exercise-induced wheezing when children begin playing sports (soccer, basketball, swimming) that challenge their endurance.

Allergies affect about 38 percent of all Americans, and about 5 percent of the U.S. population has asthma. The highest proportion of asthma is among children age 5 to 14, a total of 5 million children. Childhood asthma has increased by more than 40 percent since 1980. In other parts of the world, the numbers are even higher. In Western Europe as a whole, asthma cases have doubled in the last ten years, according to the UCB Institute of Allergy in Belgium. “The prevalence of asthma in children can be as high as 30 percent in certain populations,” explained Professor Romain Pauwels, Chairman of the Global Initiative for Asthma (GINA). “In Australia, for example, one child in six under the age of 16 is affected today. Experts are struggling to understand why rates worldwide are, on average, rising by 50 percent every decade.”

Many researchers have looked at the growing number of childhood vaccines as a likely cause of the rise in childhood asthma. Several clinical studies have confirmed an association between vaccination and asthma. A team of New Zealand researchers followed 1,265 children born in 1977. Of the children who were vaccinated, 23 percent had asthma episodes. A total of 23 children did not receive the DTP vaccines, and none of them developed asthma (Kemp et al., 1997). A study in Great Britain produced similar findings that associated asthma with the pertussis vaccine. In that study, 243 children received the vaccine and 26 of them later developed asthma (10.7 percent), compared to only 4 of the 203 children who had never received the pertussis vaccine (2 percent). Additionally, of the 91 children who received no vaccines at all, only one had asthma. Therefore, the risk of developing asthma was about 1 percent in children receiving no vaccines and 11 percent for those children who received vaccines, including pertussis (Odent et al., 1994). A third study was conducted in the U.S. from data in the National Health and Nutrition Examination Survey of infants through adolescents aged 16. Data showed that children vaccinated with DTP or tetanus were twice as likely to develop asthma, compared to unvaccinated children (Hurwitz and Morgenstern, 2000). Medications given to children early in life also have a significant effect on the incidence of asthma. Children given antibiotics or acetaminophen (Tylenol) at some time prior to age 4 were nearly twice as likely to develop asthma, compared to a control group (Cohet et al., 2004). One group of researchers discovered a possible cause for the development of asthma as a consequence of antibiotic use. Mice given antibiotics developed an alteration of intestinal bacteria and an increase in the growth of intestinal yeast. These mice developed typical allergic responses in the lungs when they were exposed to mold spores. Mice that did not receive antibiotics did not experience the allergic reactions (Noverr et al., 2004).