Allergy from infancy to adolescence

A population-based 18-year follow-up cohort study conducted as part of the Finnish Family Competence Study started in 1985 has provided information on suspected versus diagnosed allergy in infancy as predictors of allergy and asthma in adolescence.

Almost 1300 families in Finland who were expecting their first baby and making their first visit to a maternity health care clinic in 1986 were selected randomly as a study population. Once the children had been born, data were collected at the ages of 9 and 18 months and 3, 5, 12, 15 and 18 years by health care professionals, parents, and once the children had reached adolescence, they provided information themselves.

At the age of 9 months, the prevalence of suspected allergy was higher than that of actual diagnosed allergy. At the age of five years the number of suspected allergies was nil, whereas the prevalence of diagnosed allergy was about 9%. During the adolescence, the prevalence of self-reported allergy increased steadily up to the age of 18 years, while that of asthma remained at approximately 5%.

Overall, the study findings indicate that suspected allergy in infancy and at 5 years of age does not predict allergy at adolescence. Compared with children without allergies, children with a diagnosed allergy at the age of 5 were over 8 times more likely to have allergy and nearly 7 times more likely to have asthma in adolescence.

The study authors concluded that efforts need to be focused on providing families with accurate diagnosis of allergies in early childhood. Armed with this information, families can be prepared with the knowledge that a definite diagnosis of allergy at the age of 5 strongly indicates the child will remain allergic or asthmatic in their teens.

Reference: Kaila et al. 2009. BMC Pediatrics Vol. 9. Doi:10.1186/1471-2431-9-46.
Note this is an Open Access article available from: www.biomedcentral.com/1471-2431/9/46