الفهرس 
Introduction and aim of the workOnly 14 pages are availabe for public view
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Abstract
Atopic dermatitis (AD) is the most common chronic, inflammatory skin disease. It is a chronically relapsing eczematous disorder of the skin that occurs in persons of all ages but is more common in children. It has been reported to affect more than 10% of children in most countries, and 1-3% of adults worldwide. The condition is characterized by intense pruritus and a course marked by exacerbations and remissions. Patients with AD may have disrupted sleep with consequent daytime fatigue and compromised school and work quality. AD is associated with other atopic diseases such as allergic rhinoconjunctivitis or bronchial asthma. Nearly 80% of children with AD eventually develop allergic rhinitis or asthma . Skin hydration, avoidance of irritants, antihistamines, topical corticosteroids and newer topical immunomodulators are the mainstay of therapy for AD. However, AD is usually refractory to treatment and the local and systemic side effects of topical steroids are widely recognized. Leukotrienes (LTs) are a class of potent biological inflammatory mediators derived from arachidonic acid. Leukotrienes are divided into two groups according to their chemical structure: those with a sulphur linkage (cysteinyl LTs: LTC4, LTD4, LTE4), and those without(LTB4). Eosinophils, basophils and mast cells are the most important sources of LTs. There is evidence of enhanced LT production in the pathogenesis of AD.The cysteinyl LTs increase vascular permeability and dilate skin blood vessels. Patients with AD have activated circulating basophils and increased basophil releasability of LTC4.