[Preschool asthma].

PRESCHOOL ASTHMA. Any wheezing dyspnea occurring after the age of 12 months should prompt consideration of an asthma diagnosis. A chest X-ray is essential to rule out the most common differential diagnoses, allergy testing should be straightforward, and more in-depth investigations are necessary if asthma control remains insufficient despite well-conducted maintenance treatment. About 40% of preschool asthma cases persist through childhood, with risk factors including tobacco exposure, atopy, and symptom severity. Early phenotyping of asthma, even in preschool children, allows for optimized long-term management, keeping in mind that persistent early-onset asthma increases the risk of developing chronic obstructivre pulmonary disease (COPD) in adulthood.