Digital healthcare technologies, particularly given the fast developments in artificial intelligence, can assist doctors in making well-informed diagnostic and therapeutic choices. In the treatment of allergies, electronic clinical diaries have recently been used to prospectively collect patient data and improve diagnostic accuracy. This review summarizes the clinical and scientific experience gathered with a digital platform for patients with pollen allergies. The AllergyMonitor® (AM) mobile application and back-office enable patients to record their daily allergy symptoms, as well as the intake of symptomatic medication and immunotherapy and possible side effects. Results can be viewed by both the patient and the treating physician in concise reports via smartphone or computer. Many clinical studies and routine experience have shown that (A) the etiological diagnosis of seasonal allergic rhinitis (SAR) is often challenging in polysensitized patients living in areas with high levels and diversity of pollen exposure; (B) the diagnostic work-up of these patients can be aided by matching prospectively recorded symptom and pollen data in a Clinical Decision Support System (CDSS), (C) adherence to daily symptom monitoring can remain high (>80%) for several weeks if prescribed and carefully explained by the treating physician, in a blended care approach; (D) the use of mobile technology can improve adherence to symptomatic drugs and allergen-specific immunotherapy. Trials and clinical practice based on the use of AM have demonstrated the reliability and positive impact of a digital platform that includes an electronic diary (e-Diary) on allergic rhinitis patient care.