Fig. 1

Overview of in- and exclusion criteria. 1) 12% reversibility in FEV1 or positive histamine/methacholine provocation test. 2) Allergic sensitization as proven by a skin prick test or specific IgE in combination with clinically relevant symptoms triggered by culprit allergen (Ansotegui, WAO position paper 2020). 3) 400–800 mcg beclomethasone daily (or dosisequivalent of other ICS). 4) Immune suppressive drugs, such as biologicals/monoclonal antibodies, calcineurine inhibitors, mTOR inhibitors and IMDH inhibitors. 5) in concordance with the Medical Research Involving Human Subjects Act (Dutch: WMO—article 5). (BMI Body Mass Index, FeNO Fractional exhaled Nitric Oxide, OCS Oral CorticoSteroids, ICS Inhaled CorticoSteroids, FEV₁ Forced Exhaled Volume in 1 s, ACQ Asthma Control Questionaire, COPD Chronic Obstructive Pulmonary Disease)