Skin surfaces in the acne prone areas are colonized with Staphylococcus epidermidis and anaerobic gram positive Propionibacterium acnes. On the other hand skin colonization with staphyloccocus aureus have been implicated in pathogenesis of acne vulgaris. In adolescence, the number of bacteria on the skin surface increases. However, P. acnes appear to be the main organism in acne and its elimination should be addressed in any course of treatment. Studies suggest that bacteria have nothing to do with the initiation of comedogenesis. However, Propionibacterium acnes, in particular, may in some situations be important in the initiation of inflammation especially in cysts. It is also quite likely that they are involved in a perpetuation of inflammation once established. Severity of acne however does not relates to the number of bacteria on the skin surface or in the sebaceous ducts. Many topical acne treatments target bacterial control in order to subsidize acne and comedones, among them benzoyl peroxide. Long chained fatty acids have drawn attention as potential therapeutic agents for their antimicorbial activity against common skin pathogens which cause acne. Gamma linolenic acid (GLA; c18:3n-6), eicosapentaenoic acid (EPA; c20;5n-3), docosahexaenoic acid (DHA; c22:6n-3) have been subject of study for their antimicrobial activity and proved to work in synergy with skin antimicorbial protiens and benzoyl peroxide in combating staphyloccocus species and p.acnes.
Folliculitis, however clinically different from acne, has somewhat similar manifestations. Folliculitis is a somewhat nonspecific term that refers to inflammation of the hair follicle. The most common etiology of folliculitis is bacterial infection, often due to Staphylococcus aureus, a common culprit with acne bacteria. The usual clinical presentation is that of superficial pustules and/or papules in the distribution of the hair follicles; the face, chest, back, thighs, and buttocks are most-commonly body areas often involved. Folliculitis is frequently initiated by mild physical injury to the follicles, such as friction caused by tight-fitting garments, or by ingrown hairs in the beard area in men.