Thunderstorm asthma: mechanisms and prevention strategies: a prospective observational study from a tertiary allergy clinic in Eastern India

Background: Thunderstorm asthma (TA) is an environmental phenomenon in which specific meteorological conditions convert pollen into respirable allergenic particles, triggering acute asthma exacerbations in sensitised individuals. Although well documented internationally, data from the Indo-Gangetic plain remain limited. The objective of the study is to evaluate the clinico-epidemiological profile, aeroallergen sensitisation patterns, and risk factors associated with thunderstorm-triggered asthma exacerbations in patients attending a tertiary allergy clinic in Patna, and to assess effectiveness of a structured prevention and patient-education strategy. Methods: This prospective observational study was conducted at Modi Allergy Clinic, Rajendra Nagar, Patna, from March 2025 to March 2026. A total of 135 patients with physician-diagnosed asthma, allergic rhinitis, or symptoms associated with thunderstorms were enrolled. Clinical history, ARIA-based rhinitis grading, skin prick testing, spirometry, peak expiratory flow rate monitoring, and serum total IgE estimation were performed. Thunderstorm-associated exacerbations occurring within 24–48 hours during the pollen season were documented and correlated with sensitisation status. A structured prevention protocol comprising weather/pollen alerts, inhaled corticosteroid optimisation, written asthma action plans, indoor sheltering, air filtration, and mask use was implemented. Results: Most participants were sensitised to grass and weed pollens. Thunderstorm-associated exacerbations were more frequent among patients with moderate-to-severe allergic rhinitis and grass-pollen sensitisation. The prevention strategy was associated with fewer thunderstorm-related emergency visits and unscheduled exacerbations. Conclusions: Identification of high-risk patients and pre-season optimisation of controller therapy, combined with early-warning and patient-education strategies, may reduce clinical impact of thunderstorm-triggered asthma in the Indo-Gangetic plain.