Humoral immunopathological mechanisms in the skin.

Thus the skin is a unique organ in terms of location. Our skin directly interfaces with our environment and thus, unlike any other organ, is constantly subjected to foreign substances and microorganisms. Many of its structures are unique, and many of the proteins expressed by epidermal cells are also unique. Exposure to ultraviolet light affects the expression of some of these proteins as well as other biochemical substances. Although the skin also functions as an immunologic organ, it is not surprising that it can be the subject of immunologic attack. Thus, all of the major humoral immune mechanisms, cytotoxic or cytolytic, immune complex and atopic or anaphylactic, are manifested in terms of skin diseases.