Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 20 3 2021 06 06 259 262 Ian M Adcock National Heart and Lung Institute, Imperial College London, London, UK Sharon Mumby National Heart and Lung Institute, Imperial College London, London, UK 2021 04 26 2021 05 09 This letter to the editor has not an abstract. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3206 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3206/1711