Allergy march of Chinese children with infantile allergic symptoms: a prospective multi-center study

Background: Allergy march refers to progression of allergic diseases from infantile food allergy to the development of asthma and allergic rhinitis (AR). Evidence come mostly from studies in European countries. This study aimed to investigate allergy march in Chinese children with infantile food protein allergy (FPA) with a special focus on the effect of different formula interventions. Methods: From 2008 to 2010, 153 infants diagnosed with FPA were recruited in five tertiary hospitals across China. They were randomly treated with amino-acid-based formula or soy-protein-based formula for a period of 3 months. Long-term follow-up was performed when they reached early school age, using questionnaires, physical examinations, and serum-specific immunoglobulin E. Results: The overall follow-up rate was 73.20%. In patients who reached their early school years, the prevalence of physician-diagnosed AR and asthma were 43.75% and 23.21%, respectively. Only 40% of the subjects remained positive for food sensitizations upon follow-up. Twenty-six subjects receiving aeroallergen screening tests in infancy all proved negative, but upon follow-up, 65.57% were sensitized to aeroallergens (P=0.005). No significant difference between the effects of amino-acid-based formula and soy-protein-based formula on children's allergy march was observed. Conclusions: A high proportion (47.32%) of Chinese infants with early allergic symptoms developed respiratory allergies by their early school years. Most food-sensitized infants outgrew their condition several years later, but then aeroallergen sensitization often occurred. Amino-acid-based formula showed no advantages over soy protein-based formula with respect to arresting the allergy march.