Food allergy as an asthma comorbidity in children and adolescents: a practical approach through a real-world study

Introduction Several studies have shown interactions between food allergy (FA) and asthma, but the influence of FA in asthma traits has been scarcely studied. Methods A real-world retrospective observational study was conducted among patients between 3 and 18 years old referred to our Asthma Clinic from November 2014 to November 2017. Data were obtained from daily clinical practice. Only patients properly diagnosed with asthma and FA were included. Results 815 patients were included: 483 asthmatics and 332 non-asthmatics and 180 FA and 635 no FA. Food allergy was statistically more prevalent among asthma patients (p = 0.014). In a high pollen exposure area, Madrid, among subjects with asthma (121 FA, 362 no-FA), sensitization to lipid transfer protein (LTP) (p = 0.016, OR: 3.064, RR: 2.512) and pollen (p = 0.016, OR: 3.064, RR: 2.512) are risk factors to have a concomitant FA diagnosis, whereas sensitization to profilin is not. Peripheral blood eosinophils were higher in subjects with asthma and FA (≥450 eos/µL) than in asthmatics without FA (≤300 eos/µL) (p = 0.031). Blood eosinophilia, using a cut-off >300 eos/µL, was only present in the FA group. Therefore, this trait should be considered when phenotyping a patient as eosinophilic asthma. Sex had an impact on several variables: height, weight, BMI, blood eosinophils count, sensitization profile, and early-onset asthma. Conclusions Asthma and FA are closely related and the presence of FA should be investigated in every asthma patient. This study shows an association between asthma with concomitant FA and sensitization to pollen and LTP, blood eosinophilia, and growth alterations. Differences between boys and girls were also described, so a sex-specific approach is recommended.