Transdermal drug delivery
For transdermal drug delivery, “The concept is that the device produces microscopic wounds in the skin, forming channels that stay open for a few minutes. While they’re open, you can deliver medicine through the channel” to address conditions including melasma, melanosis,6 aging skin, unwanted tattoos and androgenetic alopecia, and to deliver topical anesthesia.
A split-face study that included 15 patients with atrophic acne scars showed that performing 0.5 mm automated microneedling before applying lidocaine 2.5% and prilocaine 2.5% prior to full-face microneedling at 2.5 mm depth significantly reduced pain on the side treated with microneedling and topical anesthesia.7 With very few studies in this area, gauging exactly how deeply the drug is delivered can be difficult. “You think the depth you set on the microneedling device is the depth to which the drug is being delivered, but there haven’t been any studies using confocal microscopy or tracing to tell if the drug is actually being delivered at that depth,” she says.
Transdermal delivery of platelet-rich plasma (PRP) via microneedling has become a very popular treatment for hair loss. “There are studies that support its efficacy, but not enough of them,” she said. The same can be said of microneedling plus PRP for acne scars.
Transdermal delivery of topical drugs via microneedling can contribute to the development of allergies and other adverse reactions. In one case series, three women developed facial allergic granulomatous reactions and systemic hypersensitivity because they were allergic to a component of an antiaging serum applied in conjunction with microneedling.8 “The take-home message here is that if a patient has sensitive skin, you might want to test the medication on a small spot in an area such as the forearm to make sure they don’t react to it,” she says.
It’s somewhat troubling that patients can order manual dermarollers online, Dr. Weinstein Velez added. “As dermatologists, we need to be very careful counseling patients about sanitation issues, making sure they don’t introduce bacteria” by using dermarollers. Dermatologists also must impress upon patients the importance of getting an evaluation and guidance from a dermatologist before using these devices, she said.