The efficacy and safety of non-pharmacological therapies for the treatment of acne vulgaris: A systematic review and best-evidence synthesis

BACKGROUND: Acne vulgaris is a multifaceted skin disorder, affecting more than 85% of young individuals worldwide. Pharmacological therapy is not always desirable because of the development of antibiotic resistance or the potential risk of adverse effects. Non-pharmacological therapies can be viable alternatives for conventional therapies. However, sufficient evidence-based support in the efficacy and safety of non-pharmacological therapies is lacking. OBJECTIVE: To assess the efficacy and safety of several non-pharmacological therapies in the treatment of acne vulgaris. METHODS: A systematic literature review, including a best-evidence synthesis, was performed to identify literature. Three electronic databases were accessed and searched for studies published between January 2000 and May 2017. RESULTS: Thirty-three eligible studies were included in our systematic review. Three main types of non-pharmacological therapies were identified laser- and light-based therapies, chemical peels and fractional microneedling radiofrequency. The majority of the included studies demonstrated a significant reduction in acne lesions. However, only seven studies had a high methodologic quality. Based on these seven trials, a best-evidence synthesis was conducted. Strong evidence was found for glycolic acid (10-40%). Moderate evidence was found for amino fruit acid (20-60%), intense pulsed light (400-700 and 870-1200 nm) and the diode laser (1450 nm). Initially, conflicting evidence was found for pulsed dye laser (585-595 nm). The most frequently reported side-effects for non-pharmacological therapies included erythema, tolerable pain, purpura, oedema and a few cases of hyperpigmentation, which were in most cases mild and transient. CONCLUSION: Circumstantial evidence was found for non-pharmacological therapies in the treatment of acne vulgaris. However, the lack of high methodological quality among included studies prevented us to draw clear conclusions, regarding a stepwise approach. Nevertheless, our systematic review including a best-evidence synthesis did create order and structure in resulting outcomes in which a first step towards future research is generated