Since 2015, GINA (Global INitiative on Asthma) guidelines were modified and adapted to better fit the pediatric population. Asthma diagnosis is mainly based on the results of PFT (Pulmonary Function Tests) and broncho-reversibility test in adult. GINA guidelines modified the requirements to reach a diagnosis of Asthma in children, based on the reversibility test. GINA guideline propose an increase of 12% of the FEV1 is considered as the diagnostic criterium for asthma in pediatrics.

Nevertheless, in clinical practice, most physicians base their diagnosis of asthma in children on the clinical signs presented by the patient and on the efficacy of the prescribed therapy. Also, the spirometric criterium is not sufficiently corroborated by clinical studies. No research has ever looked for the results of bronchoreversibility test in patients receiving a clinical diagnosis of asthma. For this reason, in children with a clinical diagnosis of asthma, the investigators want to look for the results of the bronchoreversibility test and validate that an increase of 12% of the FEV1 correlate with a physician-driven diagnosis of asthma in pediatrics. For further analysis the investigatorswill evaluate also the reversibility of small airways (FEF25-75) and the z-score of the results of the PFT in these children.

Inclusion criteria:

• Children aged between 5 and 18 years
• Children with a diagnosis of asthma undergoing a PFT and a bronchoreversibility test on the day of the diagnosis
• Children evaluated at the University Hospital of Montpellier (France), or at the Pediatric Allergy Unit of the University Hospital of Pavia (Italy)

Exclusion criteria:

• Children not able to perform a PFT
• Children taking drugs that could affect the results of a PFT
• Children included in other trials that don't allow them to be included in the present one

Children with a physician-base diagnosis of asthma, undergoing a bronchodilation test