ABSTRACT
The major skin diseases treated topically with antibiotics are acne, rosacea, and infections caused by Staphylococcus aureus (S. aureus). This chapter will focus particularly on the topical therapies prescribed in such diseases. The first section will discuss topical antibiotics prescribed for acne. It is relevant to summarize briefly the etiology of acne so that the use of such topical therapies is put into context of the overall disease and its therapeutic options. Acne is a disorder of the pilosebaceous duct and four major etiological factors need to be considered. Androgens control the seborrhea, a characteristic feature of acne [1]. In most patients, this represents an end-organ hyperresponse of the pilosebaceous gland to circulating androgens [2]. Androgens, along with other factors such as sebaceous lipid composition, local cytokines, and retinoids, influence the development of comedones, which represent ductal accumulation of ductal keratinocytes [3,4]. Acne is not an infectious disease, but colonization of the ducts with the commensal organism Propionibacterium acnes (P. acnes) probably play a central feature in the development of the inflammatory papules, pustules, and nodules [5,6]. The inflammation initially represents a type IV (lymphocytic) response to cytokines produced by the ductal keratinocytes and ductal microorganisms [7,8]. It is likely that topical antibiotics prescribed in acne act predominantly through their effect on the growth and function of P. acnes [9,10]. However, an effect on inflammation and comedogenesis may be important [11,12].
