A type of immune-mediated (allergic) inflammatory skin disorder that results in a itchy rash. A skin disease characterized by areas of severe itching, redness, scaling, and loss of the surface of the skin (excoriation). When the eruption (rash) has been present for a prolonged time, chronic changes occur due to the constant scratching and rubbing known as lichenification (thickening of the skin with accentuation of the skin lines to form a crisscross pattern).

Symptoms

The basic symptoms of AD have already been described. Dermatologists classify the lesions of AD into three basic categories:

• Acute lesions: These include extremely itchy reddened papules (small solid eruptions resembling pimples) and vesicles (small blister-like elevations in the skin surface that contain tissue fluid) over erythematous (reddened) skin. Acute lesions produce a watery exudate and are often accompanied by exfoliation (scaling or peeling of layers of skin) and erosion (destruction of the skin surface).
• Subacute lesions: These are characterized by reddening, peeling, and scaling but are less severe than acute lesions and do not produce an exudate.
• Chronic lesions: These are characterized by thickened plaques of skin, lichenification, and fibrous papules.