Keywords: AQUA questionnaire; athletes; atopy; FeNO EN AQUA questionnaire athletes atopy FeNO 1 5 5 03/30/23 20230301 NES 230301 Allergic sensitization and allergic diseases have been reported to have a high prevalence in athletes.[[1]] Moreover, atopy has been significantly associated with bronchial hyperreactivity and exercise-induced bronchoconstriction in elite athletes.[[3]] Sensitization to allergens is generally determined by a skin prick test (SPT) and/or allergen-specific serum IgE analysis.[5] Recently, the Allergy Questionnaire for Athletes (AQUA©),[6] a screening tool to predict atopy in elite adult athletes, was validated for screening of atopy in young elite athletes.[7] This screening tool may help with the early identification of atopy, which may burden the physical performances, and is especially helpful in young elite athletes.[5] Increased fractional exhaled NO (FeNO) levels are, considered to be an effective, noninvasive tool to assess the presence of eosinophilic airway inflammation and as tool to diagnose childhood asthma.[[8], [10]] This has also been correlated with allergic sensitization.[11] Therefore, we hypothesize that measuring FeNO levels may also be a useful noninvasive method to predict atopy in this population. The AUC of FeNO increased from 0.765 ( I p i < .0001) to 0.814 ( I p i < .0001) if we considered multiple sensitizations (participants with >=2 positive SPTs; Figure 1C), suggesting that FeNO levels might be a useful indicator for multiple sensitizations within atopic athletes. Can AQUA© questionnaire and FeNO predict atopy in early-career athletes? (C) ROC curve indicating the sensitivity and specificity of AQUA© (left) and FeNO (right) to predict atopy and multiple sensitizations (for FeNO). [Extracted from the article]