Of the dermatologic indications for radiofrequency microneedling (RFMN), the published evidence is strongest for skin rejuvenation, acne vulgaris, acne scars, and axillary hyperhidrosis, according to results from a new systematic review.
"Most devices for aesthetic purposes induce denaturation and remodeling of collagen, elastin, and other dermal structures through tissue injury and stimulating the body's wound-healing response," lead study author Marcus G. Tan, MD, told this news organization during the annual conference of the American Society for Laser Medicine and Surgery. "Radiofrequency microneedling is no exception in this regard. RFMN creates perforations in the skin and delivers radiofrequency-generated thermal energy into the underlying tissue. However, RFMN is unique in that thermal energy is delivered in a fashion that produces a reverse temperature gradient to most ablative lasers."
When using ablative lasers, which target water as its chromophore through selective photothermolysis, the temperature gradient is highest at the epidermis and papillary dermis, and decreases as it penetrates the deeper structures of the skin. In RFMN, radiofrequency energy is delivered directly to the target depth through the microneedle electrodes, thus creating a temperature gradient that is highest in the deep, target structures and cooler at the superficial structures. "This results in less unwanted epidermal heating and reduces the risk of postinflammatory hyperpigmentation," explained Tan, a resident in the division of dermatology at the University of Ottawa.
"Because RFMN is unaffected by skin chromophores, it is essentially a 'color-blind' technology and safe for use in patients of all skin phototypes. In comparison to lasers, radiofrequency energy can also be delivered to deeper structures of the skin by increasing the length of microneedle electrodes. Despite these advantages of RFMN, this technology remains utilized less frequently compared to ablative lasers for its skin rejuvenating effects."
To review high-quality medical literature related to RFMN, Tan and colleagues searched EMBASE and MEDLINE from inception to May 13, 2020, by using the terms "radiofrequency microneedling," "fractional radiofrequency," "radiofrequency needling," or "radiofrequency percutaneous collagen induction." They limited the analysis to dermatology-related randomized, split-body, or blinded studies with original data in humans. Of the 42 studies included in the final analysis, there were 14 studies of skin rejuvenation, 7 of acne scars, 6 of acne vulgaris, 5 each of striae and axillary hyperhidrosis, 2 of melasma, and 1 each of rosacea, cellulite, and androgenetic alopecia.
After reviewing the 42 studies, the study authors proposed that a strong recommendation for RFMN be made for skin rejuvenation, acne vulgaris, acne scars, and axillary hyperhidrosis, and a weak recommendation for the technology to be used for papulopustular rosacea, striae, and male-pattern androgenetic alopecia when used in conjunction with topical 5% minoxidil. There was insufficient evidence to make recommendations for its use in cellulite and melasma.
One finding that Tan described as "interesting" was the observation that RFMN was superior to Er:YAG fractional ablative lasers for treatment of rhytides on the lower face (i.e., the nasolabial, perioral, jawline and neck regions). "Secondly, we observed that one session of RFMN was able to achieve 37% efficacy of a surgical face-lift, but without any adverse effects," Tan said. "Two-thirds of the patients who received surgical face-lift developed hypertrophic scarring requiring further scar management, compared to none of the patients receiving RFMN."
Based on their review, Tan and colleagues recommend that RFMN be offered as one of the therapeutic options for patients seeking treatment for skin rejuvenation, acne vulgaris, acne scars, and axillary hyperhidrosis. "It is usually tolerable with just topical anesthesia applied 30-60 minutes before treatment, and its side effects are transient and usually resolve after 5 days," he said. "Patients should be counseled that the benefits of RFMN may have a slower onset, compared to other treatments, but it is progressive, durable, and can be used repeatedly and safely in all skin types including darker-skin phenotypes with minimal risk of adverse events."
One of the abstract section chairs, Fernanda H. Sakamoto, MD, PhD, said that RFMN devices have become increasingly popular in recent years. "The paper presented by Tan et al. is very relevant, as it compares clinical indications, parameters, and results in search for evidence of efficacy and appropriate settings," said Sakamoto, a dermatologist at the Wellman Center for Photomedicine at Massachusetts General Hospital, Boston, told this news organization. "The paper provides long-needed guidelines to clinicians and helps manage patients' expectations."
Tan acknowledged certain limitations of the study, including the lack of head-to-head studies comparing specific RFMN devices. "There are many RFMN devices available commercially, each with different capabilities and degrees of effectiveness," he said. "With more research and technological advancements since the first radiofrequency device was approved in 2002, RFMN has made significant improvements. In general, the newer generation devices produce markedly better results."
Tan reported having no financial disclosures. Sakamoto disclosed that she holds intellectual property rights with Accure Acne, Massachusetts General Hospital, and Lightwater Biosciences.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
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Cite this: Review of Radiofrequency Microneedling Studies Unveiled - Medscape - May 20, 2021.