Allergic diseases in childhood: What allergic sensitization can teach us?

RATIONALE: It has been assumed that the presence of some allergic sensitization might behave as a marker of allergy persistence. In addition, the presence of two or more allergic diseases in the same patient, called multimorbidity, may also work as a predictor of severity. The objective of this study is to describe the profile of allergic sensitization among atopic patients followed up in different pediatric allergy services in Brazil and its relation to severity of allergic disease.

METHODS: Cross-sectional study with evaluation of medical history and measurement of specific serum IgE (sIgE) for whole allergens and their components in participants between the ages of six months to eighteen years old.

RESULTS: 470 participants, 224 girls (47.7%), were divided into groups: 1 [rhinitis and/or asthma; n=111, higher prevalence of sensitization (HPS) to Dermatophagoides pteronyssinus (Dp) -87.4%]; 2 (atopic dermatitis; n=99, HPS to Dp-90.9%); 3 [food allergy, n=95, HPS to cow's milk (CM)-84.2%]; 4 (wheezing infants, n=80, HPS to Dp-32.5%). The most prevalent components were Der p 1 and 2. The presence of food allergy (OR=2.36, 95%CI=1.15-4.83), atopic dermatitis (OR=2.12, 95%CI=1.03-4.33) or multimorbidity (OR=1.68, 95%CI=1.03-2.74) were associated with more severe allergic disease. Regarding protection, monosensitization (OR=0.08, 95%CI=0.01-0.61) was the most expressive factor.

CONCLUSIONS: The prevalence of allergic sensitization to mites was high in all groups of patients in our study. The presence of different types of allergic diseases simultaneously as well as the frequency of sensitization presented an important relation with the severity of clinical manifestations.