Table 3 The evidence about thunderstorm related epidemics of rhinitis and asthma exacerbations

The occurrence of epidemics is strictly linked to thunderstorm

The epidemics related to thunderstorm are limited to late spring and summer when there are high levels of airborne pollen grain

There is a close temporal association between the arrival of the thunderstorm, a major rise in the concentration of pollen grains and the onset of outbreak

Subjects with pollen allergy who stay indoors with window closed during thunderstorm, are not involved

There is a major risk of severe asthma for subjects who are not under antiasthma correct treatment, but subjects with allergic rhinitis and without previous asthma can experience severe bronchoconstriction.