“…Most studies report a summer peak with a winter nadir; USA (Luckmann & Davis, 1991), Canada (Al-Omran, et al, 2003, Italy (Gallerani, et al, 2006), Israel (Freud, et al, 1988) and Russia (Khaavel & Birkenfeldt, 1978). Our own study in northern Saudi Arabia showed a winter low but a spring peak which coincides with the sandstorm season characterized by rise in infections and allergic conditions of the upper respiratory tract which concur with earlier studies on the spread of allergens during this season in Saudi Arabia (Kwaasi, et al, 1992a(Kwaasi, et al, , 1992b(Kwaasi, et al, , 1993(Kwaasi, et al, , 1998Sanda, et al, 2008).…”