Traditionally, lasers were the gold standard for acne scars. Specifically, ablative lasers, CO2 and Erbium, have been advocated over the nonablative lasers such as Fraxel 1550. In 2013, radiofrequency microneedling (RFM) was approved in the US and the dominance of lasers for acne scars has come under scrutiny. While there are indications for both technologies, this blog will elucidate the decision tree for which technology to use.
Fundamentally, ablative laser energy (heat) is generated outside the body and is driven into the skin at a temperature that causes ablation (vaporization) of the tissue ~ 100 C. Radiofrequency Microneedling generates it’s heat within the tissue by passing current through it. As the current encounters resistance (impedance), heat is produced to a level of coagulation ~ 65-70 C.
The number one concern with ablative laser is healing. While fractional technologies improve the downtime and risks, outcomes are sacrificed. Sometimes several treatments are recommended to match the results that fully ablative lasers would achieve. Downtimes are still around a week or longer with fractional CO2. More importantly, since the laser heats and ablates the most superficial skin layers, the risk of post inflammatory hyperpigmentation (PIH) is almost unavoidable in skin types 4-6. While PIH is reversible in most cases, it can take months in some cases. Wound care is essential with ablative lasers, particularly use of occlusive emollients, to maintain a moist wound for best healing. Unfortunately, occluding acne prone skin often leads to acne breakouts. When breakouts occur, there is risks of actually creating more acne scarring and becoming counter productive.
Healing with RFM is easier and less risky. While there are devices with uncoated needles, the author only advocates the coated or insulated needles. (Uncoated will have similar healing properties as the lasers). Using coated needles, the only injury to the superficial layers of skin are needle punctures. In essence, the device “bypasses” the epidermis. The heat generated from the RF will be in the deeper aspects of the skin, where there are no melanocytes, the pigment producing cells. While there is swelling, redness, and sometimes bruising, the downtime is less with RFM when compared to ablative lasers, usually 3-4 days (individuals do vary!). More importantly, the skin surface heals quickly (similar to microneedling) and there is no need for occlusive emollients.
The depths of acne scars is highly variable, and there can be superficial and deep scars in the same individual. This is probably the most important factor as to what technology to choose. RFM has the advantage for improving deep scars. While depths of RFM aren’t accurate in most devices, in the Genius they are. The Genius is able to reliably place coagulation zones down to 3.5mm. Of note, 3.5mm is typically much too deep to attack acne scars and typical settings are usually up to 2.5mm. Lasers can typically reach 1.5-1.7mm. The energy delivered diminishes as the pulse goes deeper because the energy is absorbed by the upper layers of the dermis. So for the superficial scars – boxcar specifically – give the advantage to the ablative lasers (Look up Dr. Lim 360 degree laser treatment). Keep in mind that the RFM devices can go superficial and treat boxcar scars too.
RFM
Positives:
- Safer for all skin types
- Less downtime
- Deeper penetration
- Less PIH risk
- Less wound care
- Safe on all areas of the body
Negatives:
- Not as good with superficial scars but can still treat them
- Doesn’t resurface so no pigmentation improvements
Ablative Laser
Positives:
- Good for superficial scars – boxcar
- Improves pigmentation
Negatives
- Long(er) downtime
- Higher risk of PIH in types 4-6
- Doesn’t treat deeper scars as well
- More wound care that can lead to more acne
- Higher risks of infection/scarring than RFM
- Can’t be used off-face as safely as RFM
Keep in mind that acne scars require multiple modalities such as TCA Cross, subcision, fillers, skincare, PRP, amniotic growth factors to achieve optimal results. Multiple treatments are always required upfront, but also as the aging process causes collagen and fat pad volume loss.
