Identification of Ige-mediated Food Allergy and Allergens in Older Children and Adults with Asthma and Allergic Rhinitis

摘要

Background and objective. Prevalence of immunoglobulin (Ig) E-mediated food allergy is primarily reported for certainpediatric populations and adults. The present study was aimed to investigate the relative prevalence of food allergy andallergens in older children and adults with asthma and allergic rhinitis.Methods. Patients (12-62 years) were screened using standard questionnaire and skin prick-test (SPT) with common foodsand aeroallergens. Specific IgE level was determined by enzyme linked immunosorbent assay (ELISA) and allergy wasestablished by blinded food challenges.Results. Of 1860 patients screened, 1097 (58.9%) gave history of food allergy. Of the history positive patients skin tested(n=470), 138 (29.3%) showed a marked positive reaction to food extracts. Rice elicited positive SPT reaction in maximumnumber of cases 29 (6.2%) followed by blackgram 28 (5.9%), lentil 26 (5.5%), citrus fruits 25 (5.3%), pea 18 (3.8%), maize 18(3.8%) and banana 17 (3.6%). The SPT positive patients showed elevated specific IgE levels (range: 0.8-79 IU/mL) againstrespective food allergens than normal controls (0.73 IU/mL, mean±2SD). Food allergy was confirmed in 21/45 (46.6%) ofthe patients by blinded controlled food challenges. The prevalence of food allergy was estimated to be 4.5% (2.6%-6.34%)at 95% confidence interval (95% CI) in test population (n=470). Sensitisation to food was significantly associated with asthma(p=0.0065) while aeroallergens were strongly related to rhinitis (p<0.01).Conclusions. Food allergy is estimated to be 4.5% in adolescents and adults with asthma, rhinitis or both. Rice, citrus fruits,blackgram and banana are identified as major allergens for inducing allergic symptoms