ABSTRACT
The physician must conscientiously and deliberately consider all of these elements in order to assess the patient with skin or soft tissue infection properly and institute appropriate care.
1.1 Anatomical Structures The skin is comprised of three layers: epidermis, dermis, and subcutaneous tissue. The principal cell of the epidermis is the keratinocyte, which produces keratin and plays a role in the immune function of the skin by secreting a wide array of cytokines and inflammatory mediators. Intact epidermis constitutes effective protection against infection by providing (1) a physical barrier to bacteria, (2) an inhibitory ‘‘acid mantle’’ resulting from hydrolysis of lipids, (3) colonization resistance by normal resident microflora, and (4) the antibacterial effects of sebaceous secretions and immunoglobulin secretion. The net result of these hostdetermined mechanisms is that infections of intact skin and supporting structures are unusual unless one or more of these mechanisms have become inoperative. Infections involving only the epidermis, such as impetigo, are well defined anatomically, are not usually associated with systemic manifestations of illness, and heal without scarring.
