As if it’s not annoying enough to have acne, did you know that 95% of us with acne will also develop scarring?!
Today, in part 1, we’re going to talk about the changes on our skin and types of scarring we tend to get from acne, and we’ll scratch the surface on treatments. In part 2, we’re going to go deeper into acne scar treatment (no pun intended).
So, let’s get started. After that pesky pimple goes away, what kind of changes does it leave on our skin? This is important to understand because addressing the issue will depend on which types of changes or scars that you have.
Acne can cause color change, ranging from red to brown or even sometimes lightened areas on the skin. The redness is a result of residual inflammation, because this process causes our blood vessels to dilate and allows more blood to come to the area, imparting a red hue. Darkened areas, which are also referred to as post-inflammatory hyperpigmentation or acne-induced macular hyperpigmentation, come about because inflammation triggers the cells that make pigment to make more pigment. Or, it causes pigment to be engulfed by inflammatory cells; or sometimes, if the inflammation is deeper, our skin’s pigment can even get trapped underneath the top layer of the skin. Most people develop hyperpigmentation—research shows that 65% of us will develop this type of discoloration from acne. Certain people are more likely to have this side effect — in particular, those that have darker skin, that tend to develop dark areas after inflammation (for example, after bug bites), those of us that are out in the sun often and don’t wear sun screen, and those of us that put off seeking care for acne. Unfortunately, sometimes we can have increased pigment in the skin even if the acne flare was mild and there was not a lot of inflammation. Lastly, sometimes we can develop lightened areas in sites of prior pimples—again this is called hypopigmentation. There aren’t great statistics on incidence of this complication.
It’s important for you to understand that color changes are NOT true scars and in general, will fade with time. Treatments can help discoloration to improve more quickly.
Acne can also cause true scars. There are 4 types of scars that you should know about.
The most common type of acne scars appear sunken in, or what’s called atrophic. These depressed scars form because the inflammation from the pimple is UNDER the skin, at the follicular infundibulum, and as it heals, our skin gets tighter at that spot—this is called contraction. Contraction pulls the scar downward, giving it that sunken in look. How deep the scar is in part depends on how severe and how deep the inflammation was from your pimple. Three types of sunken in scars are well document—ice pick scars, box car scars, and rolling scars. Ice pick scars are small with steep edges. Box car scars are deep with square edges. Rolling scars are deep with curved edges. Unless you’re a dermatologist, you don’t have to remember this, but it’s good for you to understand these concepts so you can better understand how to address the scar when the time comes.
Acne scars can also be raised or heaped up. Raised scars are often referred to as hypertrophic or keloidal scars. These types of acne scars form exaggerrated inflammation that stimulates too much collagen production from skin cells called fibroblasts. The distinction between hypertrophic and keloidal scars is based on if the scar extends beyond the location of the original inflammatory pimple—if confined to the area of the pimple, then we call these hypertrophic; whereas if they’re raised but extend beyond the site of the original pimple, then we call them keloidal. Hypertrophic and keloidal scars tend to form in areas of high tension, like on our back and on our chest and can sometimes itch or even hurt. Some people have a predisposition to keloidal scars, for example, African Americans.
Another type of raised acne scar is called called a papular scar. Papular scars are raised and either skin colored or slightly lighter than our skin and are smooth raised bumps. These tend to develop on the jawline, chest, shoulders and back.
In case you were wondering, the answer is yes—if you pick your pimples, this will increase your odds of having acne scars because you are worsening the inflammation by doing so.
Let’s shift gears and talk briefly about how to treat acne scars.
The first and MOST important step is to get your acne under control. This is critical because if you don’t address this, then you’re going to continue to have inflammation which can cause scarring.
Once you’ve got your acne tackled, then you can address the type of post acne skin change. In general, we recommend addressing discoloration before textural changes — in other words, treat the discoloration before the true scars. This is desirable because it’s going to help us appreciate the extent of true scarring that you have, which can be later treated.
Okay, let’s start with redness. This tends to be more short lived because it’s a result of inflammation that fades rather quickly. The best way to treat redness is time alone. If you have the means, see a cosmetic dermatologist or a plastic surgeon for laser treatment called PDL or pulse dye laser. This laser targets the blood vessels in the skin, causing them to close up, decreasing redness. Another light treatment, called IPL, can also help.
To address hyperpigmentation, AKA, dark discoloration, there’s a few options. Topical retinoids like tretinoin or retinol used nightly can fade darker areas by increasing skin turnover, blocking our cells from making pigment, and even causing the cells that make pigment to die off. They have the added bonus of treating your acne, too. You want to apply a pea sized amount to your entire face a few times a week (or nightly if you can tolerate it, though they tend to make the skin dry). You can pick one of these up over the counter, like Differin, from your pharmacy, grocery or online for as low as $15 per my googling today. Please note these should not be used if you’re pregnant, and data is limited if you’re breastfeeding. They also make you more sensitive to the sun, so make sure to wear a mineral sunscreen with SPF30 or above. We even recommend one that contains iron oxide, AKA a tinted mineral sunscreen, as this will help block visible light, say from your computer, which can make your dark marks worse.
If you want to combine creams, or if you can’t tolerate tretinoin, then other options include hydroquinone, azelaic acid, and nutraceuticals like a vitamin C serum or kojic acid. These in general work by blocking the enzyme in our skin that makes pigment. Hydroquinone requires a prescription from your doctor. You can use it up to twice daily for a couple of months, followed by few months break, because if you don’t, you can actually get worse darkening of the skin—this is called ochronosis. Hydroquinone is usually well tolerated by most people. Azelaic acid is available over the counter (for example, the ordinary has a 10% version for $11) and has the added bonus of helping treat acne too (antimicrobial, antikeratolytic). There’s also prescription forms of azelaic acid, 15% and 20%. You could use this twice daily to your entire face, or once in the morning and use tretinoin at night. Lastly, vitamin C serums are available over the counter and are wonderful, both for fading darker spots but for a number of other reasons including decreasing signs of sun damage — check out our podcast episode 8 to learn more about it. A few drops of a vitamin C serums applied to your entire face 30 minutes before sun exposure is the best way to use it.
Okay, beyond topical medicines, you can also do a few things procedurally to treat your discoloration. Microdermabrasion improves skin discoloration by helping with skin turnover. Chemical peels also help with both dark spots, by blocking our skin from making it’s pigment, and acne (by breaking apart skin bonds) and fortunately seem safe even in darker skinned patients, who are otherwise more susceptible to side effects from skin procedures. Peels that help include glycolic acid 35%, 20% salicyclic/10% mandolin acid, and physic acid peels. Please note that one peel generally is not enough — one recommended regimen is twice weekly for 6 sessions (reference 44,45 from Taylor et al article). Laser treatments like picosecond lasers and both non-ablative, fractional lasers are options, but these are not going to be covered by insurance and are NOT recommended for darker skin types because of a risk of scarring and worse color changes.
In terms of treating hypopigmentation, or lighter areas, in general, you can get away with topical treatments alone. Tretinoin, the retinoid we mentioned earlier, helps this type of discoloration. A gel form of Latisse (which many use to grow long eyelashes if you haven’t heard of it), called bimatoprost 0.03% gel can help even out hypopigmentation if used topically twice daily (ref 17-19 from Jennings part
No matter what type of color change that you have—whether it be hyper or hypopigmentation)—you have to wear a mineral sunscreen. Because if you don’t, you’re not going to have the same degree or rapidity of improvement.
References
Elsaie M. Update on management of keloid and hypertrophic scars: a systematic review. J Cosmet Dermatol 2021; 20: 2729-2738.
Tziotzios C et al. Cutaneous scarring: patholophysiology, molecular mechanisms, and scar reduction therapeutics. Part II: Strategies to reduce scar formation after dermatologic procedures. JAAD 2012; 66: 13-24.