Do seasons, in a warm temperate Mediterranean country, have an impact on asthma exacerbations?

Introduction: Mediterranean par excellence, the Tunisian climate is a diversified climate, characterized by a cool and wet winter and a hot and dry summer. This climate diversity is at the origin of seasonal diversity in pneumallergens and environmental factors Would there then be a relationship between seasons and exacerbations in asthmatic patients? The aim of our study was to focus the relationship between asthma exacerbations and seasons Methods: Retrospective study including patients hospitalized during 2016 and 2017 for asthma exacerbation. Patients were divided into 4 groups according to the period of hospitalization:G1:winter,G2:spring,G3:summer,G4:autumn Results: We collected 100 patients:36 in G1,25 in G2,15 in G3 and 24 in G4. The mean age was comparable in the 4 groups. There was a significant difference in asthma age(p=0.048). The lowest mean FEV1 was observed in hospitalized patients in autumn and winter(59 and 63%,p=0.155). Hospitalization through emergencies was found mainly in summer, while in autumn it was mostly through consultations(p=0.036). There was no significant difference in mean hospital stay between seasons(p=0.57). The most common triggering factor in the groups was viral infections. In G1and G3, the treatment stop came in 2nd position. In G2 and G4, it were infectious pneumopathies. Severe exacerbations were more frequent in summer and autumn(p=0.387). We found no statistically significant differences between groups in gasometric, biological and radiological data. The evolution was favorable in the 4 groups Conclusions: Our study shows that seasons can have an impact on the severity and on triggering factors of an asthma exacerbation. Thus a better knowledge of the triggers is essential to propose prevention oriented and adapted according to the season