Diet and acne: a review of the evidence.

Pharmaceutical acne treatments are costly and have potentially severe side-effects. Adolescent acne is typically the result of clogged, infected, pilosebaceous follicles. Adults may experience fewer comedones and more inflammatory lesions. 1 Normally, sebum travels up the follicle to the skin surface. Hormones may increase sebum production and cause follicular cells to hyperproliferate and block the follicular opening, forming a comedo. 4 Complete follicle blockage results in closed comedones (i.e. “whiteheads”), whereas incomplete blockage results in open comedones (“blackheads”). Comedo formation typically occurs over the course of 2–3 weeks. Acne may manifest in the form of noninflammatory comedones, superficial inflammatory lesions (papules, pustules), and/or deeper inflammatory lesions (nodules, cysts). Inflammatory lesion formation occurs most commonly when Propionibacterium acnes colonizes the pilosebaceous unit, triggering follicular rupture and a neutrophil cascade. 5