Epidemiology of atopy in 220 children. Diagnostic reliability of skin prick tests and total and specific IgE levels.

BACKGROUND: We have prospectively studied 220 children attending our Division because they suffered from atopic dermatitis (AD), asthma, and allergic rhinitis (AR), to assess the epidemiology of atopic diseases, and effectiveness of the diagnostic tests commonly used in allergic children.

METHODS: Among the 220 children there were 142 males (64.5%) and 78 females (35.5%) aged as follows: 57 (25.9%) 0-2 year-old, 48 (21.8%) 2-4 year-old, 49 (22.3%) 4-6 year-old, 66 (30%) >6 year-old. The diagnosis included family and personal history, physical examination, skin prick tests (SPT) and total and specific IgE (sIgE) levels. We tested inhalant and food allergens.

RESULTS: There were 101 asthmatic, 88 with AD, and 31 children with AR. The analysis of variance confirmed the age influence of PRIST with a high significance (p=0.0001). SPTs were prevalent in all groups for Der p, but casein only in 1 group, and Lolium perenne only in 2 groups. RAST showed a higher uniformity, that is CM (cow's milk) and egg for one group, Der p and Lolium perenne for the remaining groups Several correlations among diagnostic tests and the age of children were evaluated with the analysis of variance.

CONCLUSIONS: We emphasize that atopic diseases are genetically transmitted, that AD develops at a younger age than asthma (p=0.0052), and that SPTs have a greater effectiveness for inhalant allergens, positive at all age levels; in food allergy (FA) SPTs are less adequate and feasible.