Demand for safe, less aggressive and cost-efficient treatment modality to improve skin quality and appearance following scarring or photoaging is increasing steadily. A treatment modality that preserves the epidermis while promoting regeneration rather than cicatrization would be ideal. Percutaneous collagen induction (PCI) therapy or microneedling is claimed to approach this ideal objective. The current comprehensive literature review is intended to analyze the scientific basis supporting this therapeutic modality and to evaluate the efficacy of PCI microneedling therapy versus no treatment of patients with photoaged skin and scars of various etiologies on aesthetic skin rejuvenation, skin tightening and scar quality in prospective, retrospective and experimental studies. Twenty-five published studies were identified and included in this review. Four publications are experimental animal studies; most clinical reports are case series or small cohort non-randomized studies or trials lacking methodological unity with a heterogenous mix of scars, wrinkles and skin laxity being treated. The majority are studies about management of scars of various etiologies while only 4 specifically investigated the effect of PCI on wrinkles and aging skin. One study compared burn scar erythema in the treated area to the untreated area, and 5 studies included histologic evaluation of biopsies. Despite PCI promising therapeutic benefits and its increasing cosmetic applications, the current literature review unfortunately revealed a limited number of high-quality studies mostly experimental. Data and conclusions of clinical studies must be carefully interpreted before translating the evidence presented into clinical recommendations. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
Keywords: Microneedling; Non-surgical cosmetic; Percutaneous collagen induction.