Atopic eczema and the allergist

Several decades ago, the skin was considered to be little more than a simple barrier to dehydration, environmental toxins, and extrinsic bacteria; however, we now recognize that the skin is a complex immune organ that is fully integrated with the immune functions of the bone marrow, lymph nodes, liver, and spleen. Lymphocytes possess a surface glycoprotein, referred to as the cutaneous lymphocyte-associate antigen (CLA), which specifically binds to the skin. The Langerhans cell is the primary antigen processing cell in skin, and they have been shown to traverse to regional lymph nodes where they then have an opportunity to network with lymphocytes that traffic to and from the skin. This paints the picture of the skin as being a very dynamic immune organ that is totally integrated with the other immune organs and effector cells of the body. This discussion will review clinical complexities of atopic dermatitis as a prototype of allergic skin disease.