Body Mass Index and skin reactivity to histamine and Dermatophagoides pteronyssinus in children and adolescents followed in a pediatric allergy service.

Summary Rationale. Recent data suggest that the nutritional status assessed by body mass index (BMI) is positively associated with skin reactivity to histamine in children. Objective. To study the relation between BMI and skin reactivity to histamine and Dermatophagoides pteronyssinus in allergic children and adolescents. Methods. The medical charts of patients attended in our outpatient clinic between 2013 and 2014 (n = 972) were evaluated. Only patients with asthma, allergic rhinitis or wheezing infants sensitized to at least one aeroallergen were selected: a total of 626 patients (6 months to 19 year-olds; 60.1% male) were enrolled. Weight (kg), height (m), BMI (weight/height2), and the mean diameter of the wheals induced by histamine (10 mg/ml) and Dermatophagoides pteronyssinus in skin prick tests (SPT) were obtained. Skin index (SI; ratio of allergen-induced wheal diameter and corresponding histamine diameter) was also analyzed. Results. All patients had shown a mean wheal diameter of histamine greater than 1 mm. There was no increased skin reactivity to histamine with increasing BMI Z score (ZBMI). However, a significant correlation between BMI and the mean wheal of histamine was observed in patients < -1 ZBMI. Similar results were observed with Dermatophagoides pteronyssinus, (even considering the SI). Conclusions. We did not document interference of nutritional status (ZBMI) on the skin reactivity to histamine or Dermatophagoiodes pteronyssinus in atopic patients. Further investigation is required.