Many of our patients have come to us very frustrated with the previous information or acne scar treatments they have received. There are many acne scar treatments being promoted, a few of which can be effective and many that are not. Today I am going to talk a little about the physiology of acne scarring and which treatments are most likely to be effective.
Acne scarring results when the healing process after an acne infection goes array. After the skin is inflamed by the acne lesion, fibrosis can occur. This is made worse when patient repeatedly pick or squeeze their lesions. Picking causes repeated trauma and increased inflammation while squeezing can drive infectious material deep into the wound again causing more inflammation. Fibrotic repair of the lesions lead to the textural changes associated with acne scarring.
Anatomy of Acne Scarring:
The main thing to understand is that acne scarring lesions tend to be very deep in the skin. To give an idea of scale, most human hairs are about 100-200 microns thick. Acne lesions normally extend between 800-2000 microns (.8mm-2mm) into the skin. This fact alone explains why most acne scar treatments are minimally effective.
Solutions to Acne Scarring:
The most obvious solution to acne scarring is prevention. Scarring develops during the inflammatory and healing stages of the lesion so there are a couple of ways to prevent it. First is to keep acne, especially cystic acne under control. This involves a visit to the doctor and normally some type of education and prescription topical or oral medication. TV infomercials are not a replacement for a visit to your physician. There are many patients whose acne goes from very controllable to fairly severe because they try months or years of over the counter treatment options that never quite work. The second part is simply not to pick or squeeze acne lesions. Picking and squeezing are both inflammatory and make lesions worse.
Acne Treatment Options:
Tretinoin (Retin-A) is one of the very few topicals that has been shown to improve the appearance of acne scarring in peer reviewed clinical trials. Patients should be very suspicious of any product claims that do not compare their product to either a placebo or Tretinoin.
Microdermabrasion and Superficial Chemical Peels:
Mild fruit acid peels such as Glycolic, Lactic, Salicylic and microdermabrasion are often offered up as treatments for acne scarring. Most of these treatments penetrate from 10-30 microns into the skin, remember acne scarring normally goes from about 800-2000 micros into the skin. That means even at their best, these treatments only effect the top 5% of the scar. With multiple repeated treatments this can be slightly increased but even after 10-20 treatments with these modalities there are only modest results at best.
TCA, multiple layer Jessner ‘s Solution can penetrate through the epidermis over 100 micros into the skin. These products use a chemical reaction to literally burn a thin layer of skin off. The deeper the lesion caused by the peel, the longer the downtime will be. Peels that do deep enough to completely remove the epidermis will normally take about 7-10 day to recover from but still will only treat about the top 10-20% of an acne scar. Phenol peels are very deep peels which although they can get moderate results are not used very often any more do to their potential for scarring.
Non Ablative Lasers:
This a large category which includes any light based technology that heats the skin to stimulate collagen synthesis which helps fill in depressions in the skin. The heat also helps rearrange the abnormal architecture of collagen fibrils that are already present. Light sources such as Cutera’s Laser Genesis and the Fraxil Re:store fall into this category. With all of the light sources the energy of the laser is absorbed by water in the tissue and turned into heat. These procedures require multiple treatment but can provide moderate results with little to no downtime.
Shallow Ablative Lasers:
An ablative laser actually vaporizes (destroys) an area of tissue. The shallow lasers are normally Erbium devices such the Cutera Pearl and Sciton Contour or Profactional. These lasers come in versions that treat the entirety of the skin and in fractional versions which only treat a small portion of the skin (like aerating a lawn). The advantage of the fractional devises is that they tend to go deeper which treats deeper pathology and significantly decrease both heeling time and side effects. Erbium lasers will tend to product about 30-150 microns of ablations in the full forms and about 600-800 microns in their fractional forms. The fractional version of these lasers can provide nice improvement in acne scarring but have two draw backs. The first is that even the fractional versions of Erbium lasers to not get to base of most acne scars and second is these lasers do not provide as much heat to tissue as a CO2. This heat is necessary to induce remodeling of the tissue that is not ablated and is a major factor in the final outcome that a patient sees in the mirror.
Deep Ablative Devices:
Almost all of the lasers currently in this category are CO2 lasers. This is the gold standard in revising acne scarring. The newest devices are fractionated like their more shallow counterparts. There are many devices in this category including, Pixel, Affirm, Dot, Fraxil Re:pair and Lumenis Active FX and Deep FX. Unfortunately most of them are grossly underpowered. Underpowered lasers need to use very long laser pulses to get the same amount of energy into the tissue as a short pulse with a properly powered laser. These long pulses can lead to excessive tissue heating and side effects such as discoloration and even scarring. These underpowered devices are cheap to build and more affordable to purchase so they have become very common in the medi-spa industry. I will only go into detail about the appropriately powered devices such as the Lumenis Active FX, Deep FX and Fraxil Re:pair. These devices can penetrate 2000 microns into the skin or more and thus are the only devices that can reach the entire scar region. Although good results can be obtain with both devices the clear king of the mountain is the Lumenis laser. In a study done a Johns Hopkins 9 out 10 patient preferred both the procedure and results from the Active FX when compared to the Fraxil Re:pair.
There are many other treatments including subcision, needling, punching out lesions and adding filler that can all be used to improve the texture of acne scarring. Although these modalities can be effective, they tend to be more useful for less extensive lesions.