INTRODUCTION : Asthma is the most common chronic disease of childhood and its prevalence has substantially increased worldwide, particularly in pre-school children (Masoli et al., 2004). According to many investigators asthma prevalence is above 10% in most developed countries & expected to be twice in 2020(Movahedy, 2000;Tepas et al., 2001, Liu et al., 2004,Lodrup et al., 2006). In chil...