Supplementary Material for: Peanut inhalant challenge in peanut allergic children and adolescents

Introduction: The risk of allergic reactions due to airborne exposure to peanuts remains uncertain. Although a few small studies indicate that this risk is low, further evidence is needed. We aimed to assess the risk of allergic reactions during a standardized, open peanut inhalation challenge in a large cohort of peanut allergic children and adolescents.
Methods:
Patients aged 5–18 years with probable peanut allergy were recruited to undergo a standardized inhalation challenge. Inclusion criteria were either having a history of allergic reaction involving more than one organ system and having Ara h 2 > 2,0 kU/l or having no known exposure and Ara h 2 > 5,0 kU/l. Participants were exposed to an open bag of peanuts positioned 30 cm from the nose for 10 minutes, followed by a 20-minute observation period. Spirometry and physical examination were performed before and after the challenge. Data were collected on previous peanut reactions when available, atopic comorbidities, specific IgE levels for peanut and Ara h 2, and family history. Allergic responses were classified as subjective or objective. Objective reactions were defined as visible or measurable signs, including urticaria, erythema, rhinitis, conjunctivitis, angioedema, or respiratory symptoms (e.g., stridor, wheezing, or ≥12% reduction in forced expiratory volume in 1 second (FEV1) from baseline). Subjective reactions were defined as symptoms other than those defined as objective.
Results:
A total of 323 children and adolescents with probable peanut allergy completed the inhalation challenge. Fifty participants (15.5%) showed possible allergic reactions during or after exposure, of whom 10 (3.1%) exhibited objective reactions. Only four (1,2%) participants received medical treatment. No severe adverse events occurred, and no participants required hospitalization.
Conclusion:
The findings indicate that the risk of significant allergic reactions from airborne peanut exposure is low. These results may offer reassurance to patients, caregivers, and healthcare professionals regarding the safety of being in proximity to others consuming peanuts.