Therapeutic Update: Acne

March 2014 | Volume 13 | Issue 3 | Features | 235 | Copyright © March 2014

Whitney Bowe MD and Mary-Margaret Kober MD

SUNY Downstate Medical Center, Department of Dermatology, Brooklyn, NY

Acne vulgaris is a multi-factorial disease affecting a significant proportion of the population. A patient-centered approach is most effective for the treatment of acne, focusing both on life style interventions as well as pharmacologic therapy. Lifestyle modifications include dietary counseling, as a link between dietary choices and acne continues to grow. Pharmacologic regimens must account for the severity of disease, emergence of resistant bacterial strains and ease of patient compliance. Combination topical therapy is often required for patients with mixed inflammatory and comedonal acne, while oral medications are frequently needed for severe cases or those involving large surface areas such as the chest or back. With or without a photosensitizer, light based treatments present an alternative or adjuvant to traditional pharmacologic therapy. Novel formulations of existing medications in addition to original compounds continue in development, expanding therapeutic possibilities for the future. With the emergence of antibiotic resistance, we are forced to prescribe antibiotics more responsibly, while exploring alternatives to this longstanding standard of care. This article discusses current and emerging therapies for the treatment of acne.
table 1
table 2
Acne vulgaris is the most frequent primary diagnosis reported by dermatologists.1 To some degree, it affects nearly all adolescents, presenting as comedones, papules and pustules and in severe cases nodules and cysts.2 Acne pathogenesis relies on four primary factors: excess sebum production, Propionibacterium acnes (P. acnes) follicular colonization, abnormal keratinization and inflammation. While abnormal keratinization resulting in the microcomedone was classically considered the first step in the acne process, we now know that inflammation is the inciting factor, working through Toll-like receptor (TLR)- 2.3 To combat the multiple factors of acne pathogenesis, while simultaneously addressing an increasing desire for natural and alternative therapies, lifestyle interventions as well as pharmacologic therapy characterize the holistic approach most acne patients require.

Lifestyle Interventions

The evidence supporting a link between diet and acne continues to grow, with high glycemic index diets and dairy consumption emerging as the most consistent triggers. Adolescent patients placed on a low glycemic index diet showed a significant decrease in free androgen index and acne severity.4,5 Biopsy specimens of acne lesions performed at baseline and at ten-weeks demonstrated a decrease in the sebaceous gland size, the number of inflammatory cells and the expression of inflammatory cytokines, such as interleukin-8.5 Foods with high glycemic indices include white bread, white potatoes, pretzels, chips, cornflakes and white rice, while multigrain bread, beans, vegetables and proteins and seeds illustrate examples of foods with a low glycemic index. Certain dairy beverages, specifically skim milk, also appear to contribute to acne formation. Although retrospective and based on patient reporting, food consumption questionnaires showed an increased risk for acne development in those who consumed milk or ice cream.6 No association was seen with yogurt or cheese consumption.6 High glycemic index foods and dairy consumption increase androgen levels and insulin-like growth factor-1(IGF-1); IGF-1 controls signaling of the Fox01 nuclear transcription factor. 7,8 Fox01 in combination with nutrient-sensitive kinase mTOR complex 1 signaling are currently hypothesized to be the primary mediators of food-induced acne promotion7,8; however, more research is required to fully elucidate this mechanism.
While most dairy products seem to exacerbate acne, a notable exception appears to be yogurt. In fact, yogurt with live active cultures, or probiotics, seems to be protective when it comes to the development of acne. Probiotics seems to impact acne through what has become known as the “gut-brain-skin axis”.9 Psychological distress alone, or in combination with refined, processed foods, slows gut motility and alter gastrointestinal flora, leading to increased intestinal permeability. This in turn leads to systemic inflammation and decreased insulin sensitivity, and the cascade of events is thought to promote acne in predisposed individuals. Oral probiotics have been shown to normalize the gut