Received: 23 April 2021
Accepted: 29 July 2021
First Online: 9 August 2021
: Data were obtained retrospectively, all interventions were conducted as part of regular patient care and used strictly anonymously, according to the principles of the Declaration of Helsinki and the code of conduct for medical research approved by the hospital’s Medical Ethical Committee. Parents gave their written informed consent before starting the challenge tests.
: Not applicable.
: The authors declare that they have no competing interests.