Sykor iFrax:  Why Fractional RF Treatments Are Safer for Treating Dark Skinned Patients

Since the advent of “ablative” CO2 laser skin resurfacing in the early 1990’s, the focus of medical aesthetic devices has been on the epidermal (most superficial) skin layers. “Non-ablative” technologies emerged in the late 1990’s with the intention of minimizing the he side effects and down time requirements incident to light-based skin rejuvenation and resurfacing treatments. In contrast to ablative rejuvenation procedures, non-ablative laser rejuvenation procedures induce a dermal healing response without notable injury to the epidermis. Improving the appearance of the skin without injury to the epidermis is a hallmark of non-ablative skin rejuvenation.  It is believed that sub-threshold laser-induced injury to the dermis and/or the dermal vasculature theoretically results in a wound repair response, fibroblast stimulation, and collagen reformation. The only problem with non-ablative procedures has been that—for the most part—patients and practitioners were not totally satisfied with the results achieved.

 

With both ablative and non-ablative procedures, the effect of laser treatment is always the greatest at the skin surface—and less beneath the skin surface. Since the dermis is always protected by the epidermis—and you always have to go through the epidermis to reach the dermis– with lasers there is always some degree of dermal impact. With fractional RF(FRF) technologies, for the first time ever it is now possible to minimize or completely bypass epidermal impact because of the nature of RF energy delivery. FRF systems are capable of delivering RF energy to the skin in either a “pyramid shape” due to the nature of FRF energy delivery or directly to the dermal layers due to the high conductivity of stainless steel needles. With sublative systems, RF energy is delivered through a tiny epidermal ablation which then spreads laterally as it travels deeper into the skin.  Sublative energy (shown below) delivery allows the use of higher energy levels that can create greater temperature increases in the deeper dermal skin layers.

More advanced fractional RF devices—such as the iFRAX System– incorporate large numbers of specially designed, fine  micro-needles which penetrate the skin causing both physical micro-trauma and with each puncture together with simultaneous micro-delivery of fractional RF energy.  These “micro-needle” FRF devices deliver RF energy to the skin via stainless steel needles. Since stainless steel has significantly higher electrical conductivity than human skin, the RF energy travels directly down each needle and the between the alternately positive and negative needles (as shown below) with little or no energy being delivered to the skin (except at the desired target point typically in the dermal layers) due to the much higher electrical impedance of the skin.  As a result, only the targeted tissue at the precise level to which the needles are inserted is heated. By setting the needles to be inserted 1 mm or deeper, it is possible to completely bypass the epidermis and avoid complications for darker-skinned patients.

Highly ablative fractional treatments are generally not recommended for darker skinned patients due to extensive impact at the epidermal skin level and the tendency for darker skinned patients to experience adverse events such as post-inflammatory hyper-pigmentation (PIH). Skin color is determined by cells called melanocytes.  Melanocytes are specialized cells within the skin that produce a pigment known as melanin. Melanin is produced and stored within special structures, known as melanosomes, contained in the melanocytes. Most melanocytes are located in the basal layer of the epidermis as shown below:

The variation in skin color we see across all people is determined by the type and amount of melanin produced by their melanocytes. Melanocytes are stimulated by ultraviolet (UV) light from the sun as well as excessive heat.  People with skin of color have more active melanocytes than those with light skin, so they produce more pig-ment. This production increases when stimulated by light exposure or rising hormone levels. Darker-skinned individuals also have hyper-responsive melanocytes. Therefore, any type of skin inflammation – including excessive skin heating—can trigger melanogenesis resulting in PIH and other adverse reactions to some treatments.

TYPE I: Highly sensitive, always burns, never tans. Example: Red hair with freckles.

TYPE II: Very sun sensitive, burns easily, tans minimally. Example: Fair skinned, fair haired Caucasians.

TYPE III: Sun sensitive skin, sometimes burns, slowly tans to light brown. Example: Darker Caucasians.

TYPE IV: Minimally sun sensitive, burns minimally, always tans to moderate brown.
Example: Mediterranean type Caucasians, some Hispanics.

TYPE V: Sun insensitive skin, rarely burns, tans well. Example: Some Hispanics and some Blacks.

TYPE VI: Sun insensitive, never burns, deeply pigmented. Example: Darker Blacks.

 

The treatment of darker skin phototypes can be challenging with light-based devices because of the interference of epidermal melanin absorption of laser and IPL energies, in addition to hyper-responsive melanocytes which can react to any treatment delivering heat to the epidermis.  As epidermal melanin increases, the occurrence of cutaneous side effects such as dyspigmentation, blistering, and crusting become more problematic.  Since “micro-needle” FRF devices such as the iFRAX System can deliver RF energy directly to the dermal layers while bypassing the sensitive epidermis, it is finally possible to achieve great skin rejuvenation and anti-aging results without the adverse events and complications seen with darker-skinned patients with light-based treatments.