INTRODUCTION
Asthma is derived from the Greek word meaning “to stay in order to breathe or difficulty in breathing”.1 Bronchial asthma is a condition of the lungs characterized by widespread narrowing of the airways due to spasm of the smooth muscle, edema of the mucosa, and the presence of mucus in the lumen of the bronchi and bronchioles. It is caused by the local release of spasmogens and vasoactive substances in the course of an allergic reaction.2 According to World Health Organization (WHO-2010) 300 million people worldwide were affected by asthma leading to approximately 250,000 deaths per year.3 It is the most common chronic illness in childhood and is one of the most common causes of admission to the hospital among children and adults