In chronic diseases, mHealth apps help to improve clinical management and provide valuable real-world scientific evidence. In allergic rhinitis, a market research study identified only 4 mHealth apps that were multilingual, resulted in scientific publications, and displayed a comprehensive list of medications. Of these 4 apps, MASK-air® generated the highest number of scientific publications. MASK-air was launched in 2015 and is currently available in 30 countries, with data collected from more than 30 000 users. It comprises a daily monitoring questionnaire, enabling patients to register their daily allergy symptoms by means of visual analog scales and their medication use. The achievements of MASK-air include the development of 2 digital biomarkers for daily monitoring of rhinitis and asthma (combined symptom-medication score and electronic daily asthma control score). MASK-air data have also made it possible to assess patients’ behavior, suggesting that patients do not follow guideline recommendations, but rather treat themselves (and often use comedication) when they feel worse. Using MASK-air data, we quantified the impact of allergic diseases on quality of life and school and work productivity. Realworld MASK-air data are being used as a source of evidence for the Allergic Rhinitis and its Impact on Asthma 2024 guidelines in an innovative process of incorporation of mobile health data into guidelines. This review discusses the clinical and scientific contributions of MASK-air to person-centred care of rhinitis and asthma, providing an illustrative example on the use of mHealth data in chronic diseases.

Key words: Allergic rhinitis, Asthma. mHealth, Patient-reported outcome measures