Analysis and measurement of sixteen common allergens in children with respiratory disorders in Guangzhou

Objective To explore the sensitization of 16 common allergens in children with respiratory diseases in Guangzhou, and to investigate the differences of allergens positive rate and compare the sensitization severity of two different age groups. Methods From August 2007 to March 2008, 320 children primarily diagnosed as bronchial asthma, allergic rhinitis or respiratory infections in our respiratory or pediatric department as out-patients were enrolled in the study. In those children, 214 children were no more than 3 years (infants group) and 106 children were more than 3 years (elder children group). Specific IgE (SIgE) antibodies of sixteen common allergens were measured by serologic test with immunocapture methods using ALLERG-O-LIQ-SYSTEM (Dr. Fooke Laboratory, Germany). Results Fifty-nine cases(18.44%) were SIgE negative and 261 cases (81.56%) were SIgE positive. The positive rates of SIgE for 16 common allergens were Dermatophagoides pteronyssinus (36.88%), Dermatophagoidesfarinae (35.31%), tropical mites (24.06%), dog furs (6.56%), cat furs (8.75%), German cockroach (16.56%), honey bee venom (0.94%), house dust (45.63%), whole-eggs (45.94%), milk (46.25%), wheat flour (6.88%), corn flour (1.25%), peanuts (9.06%), soybeans (5.94%), crabs (2.81%) and shrimp (4.38%). The SIgE positive rate was 81.78% in infants group and 81.13% in elder children group(X2=0.02,P=0.89). Allergy to foods (such as milk, whole-eggs) was more common in infants group, while allergy to inhalational allergens (such as dust mites) was more common in elder children group. For dust mite allergies, the SIgE positive rate was higher in elder children group than that of infants group(P<0.05). The elder children group had stronger response more than grade 3 to Dermatophagoides pteronyssinus and Dermatophagoides farinae. The SIgE positive rate in different grades was not significant in infants group. And weak responses mostly less than grade 3 to tropical mites were shown in both groups. For milk and whole-eggs allergies, the SIgE positive rate was higher in infants group than that of elder children group(P<0.05). Responses less than grade 3 to milk and whole-eggs were shown in both groups. Conclusions The overall rate of sensitization is not different between infants group and elder children group. The differences of incidence and sensitization severity caused by allergens should be noted. The predominant causes of sensitization are inhalational allergens in elder children group, and food allergens in the infants. The results of allergen based on children age should be analyzed. Key words: Child;  Respiratory tract disease;  Allergens;  Specific immunoglobulin E; Anaphylaxis