Sensitization to food and inhalant allergens in relation to atopic diseases in early childhood: a birth cohort study

Usefulness of open mixed nut challenges to exclude tree nut allergy in children

Background

To minimize the risk of accidental reactions, atopic children with multiple sensitizations to tree nuts are advised to avoid all nuts. Multiple food challenges would be needed to confirm the clinical relevance, but are too burdensome to be practical.

The usefulness of open mixed nut challenges in terms of safety, reactions during challenge, tolerance of the challenge material, effect on the elimination diet and satisfaction of the parents was evaluated.

Findings

Open mixed nut challenges were performed in 19 children with a previous negative hazelnut challenge and long term elimination diet for tree nuts. Challenges were negative in 13 (68 %) children, in four (21 %) children (non-severe) allergic symptoms were observed. The challenges were well accepted, safe and efficient. We were able to avoid multiple nut challenges in 15 (79 %) children.

Conclusions

Open mixed nut challenge can efficiently exclude multiple tree nut allergies in children with a lifelong nut free diet and low suspicion of clinical allergy.

Low cord blood vitamin D levels are associated with increased milk sensitization in early childhood

BACKGROUND

The association between vitamin D status at birth and allergen sensitizations is uncertain. The aim of this study was to investigate the relationship between cord blood vitamin D status with allergen sensitizations and the development of atopic diseases in early childhood.

METHODS

Children aged 0 through 4 yr from a birth cohort in the Prediction of Allergies in Taiwanese Children (PATCH) study were enrolled. Serum levels of 25-hydroxyvitamin D (25(OH)D) in cord blood were measured by a new automated electrochemiluminescence-based assay. Specific IgE antibodies against food and inhalant allergens were measured at 6 months, and 1, 1.5, 2, 3, and 4 yr of age.

RESULTS

A total of 186 children were regular followed up at clinics for a 4-yr follow-up period. The mean level of cord blood 25(OH)D was 23.8 ± 9.5 ng/ml with a high prevalence of low vitamin D status (<20 ng/ml) at birth (42%). There was a tendency of low cord blood 25(OH)D levels being associated with higher risk of food sensitization throughout childhood. Cord blood 25(OH)D levels were inversely associated with the risk of milk sensitization at age 2, at which age a higher prevalence of milk sensitization was significantly associated with the risk of allergic rhinitis, and asthma development at age 4.

CONCLUSIONS

Low cord blood vitamin D levels appear to be associated with increased milk sensitization but not with asthma, eczema, or allergic rhinitis in early childhood.