Among children with allergic disease, especially food allergies, increased exposure to grass pollen is associated with obstructive lung function deficits that are reversible, according to studying findings published recently in The Journal of Allergy and Clinical Immunology: In Practice.

Pollen increases the risk of hospital visits for children with asthma, and children with food allergies or eczema have increased risk of asthma. However, the associated risk represented by pollen for children with asthma and comorbid food allergies or eczema is unknown. Researchers therefore sought to investigate the association between grass pollen and lung function in children with food allergies.

To accomplish this, they conducted a retrospective examination of the Australian HealthNuts cohort study, analyzing data from 641 children with measured spirometry during grass pollen season who participated in the HealthNuts 6-year follow-up. Grass pollen levels were accounted for on the day of testing (lag 0), from 1 to 3 days before testing (lag 1-lag 3) and cumulatively (lag 0-3). Linear regression was used to help understand the relationships between asthma, hay fever, eczema, and food allergies.


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Only children with allergic disease showed associations with grass pollen (P ≤.1). Among children with food allergies, grass pollen concentration was associated with lower ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) and lower mid-forced expiratory flows (FEF25-75%) at all lags (eg, at lag-2, FEV1/FVC z score = -0.50; (95% CI, -0.80 to -0.20) and FEF25-75% z-score = -0.40; (95% CI, -0.60 to 

-0.04) per 20 grains/m3 pollen increase, and increased bronchodilator responsiveness (BDR) at lag-2 and lag-3 (eg, at lag-2, BDR = 31 [-0.005, 62] ml). Among children with asthma, greater grass pollen levels were associated with lower FEF25-75% and increased BDR. Children with hay fever or eczema had increased BDR only.

Researchers concluded that “increasing short-term ambient grass pollen exposure was associated with reversible obstructive lung function deficits in children with allergic disease, with the greatest risk of symptomatic exacerbation in food allergic children.” 

Study limitations included: 1) selection bias; 2) using grass pollen measurements to represent individual-level exposure; 3) underpowered sampling to investigate some specific food allergies; 4) spirometry was tested during low-moderate grass pollen levels for 95% of participants.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Idrose NS, Vicendese D, Peters RL, et al. Children with food allergy are at risk of lower lung function on high pollen days. J Allergy Clin Immunol Pract. Published online April 7, 2022. doi:10.1016/j.jaip.2022.03.022