How to heal acne scars effectively

So you’ve finally gotten your acne under control, but now you have to deal with the aftermath. Depending on the type of acne you have, you may have one type of scarring or a combination. Read on to learn how to identify and treat the different types of scars acne may leave behind.

When people say “acne scars” they’re generally referring to one of two possibilities: pigmentation or physical scarring. While technically not scars in the clinical sense, the red, purple or dark marks left post-acne are incredibly common, so let’s make sure we understand those first. 


There are two types of discoloration you may experience: PIE and PIH. Both have to do with your skin’s inflammatory response to acne.

PIE stands for post-inflammatory erythema, which can be identified by reddish-pink marks left post-acne. PIE is caused by damage to blood vessels and capillaries near the surface of your skin. This type of discoloration is more common in lighter skin tones and the most easily resolved (it still takes work, though!)

PIH stands for post-inflammatory hyperpigmentation, which can be identified by dark, purple-brown marks left post-acne. PIH is caused by the overproduction of melanin in response to inflammation. This type of discoloration is more common in medium to deep skin tones and is harder, though not impossible, to resolve, as you need to interrupt the entire melanin production process, which begins below the surface of your skin.

Ingredients to help reduce PIE and PIH

Daily, diligent sunscreen use is crucial to heal both PIE and PIH, as well as to prevent it in the first place.

With PIE, you want to focus on calming the inflammation and strengthening your skin barrier, so look for ingredients like niacinamide, panthenol, allantoin and beta glucan. Retinoids, azelaic acid and mandelic acid may also help when used in moderation with other skin soothers and strengtheners. Remember, you’re not trying to lift pigment, but rather calm the skin. 

PIH requires more time to resolve as you need to both lift excess pigment from within your skin and fade the marks on the surface. Use a combination of exfoliators, like mandelic acid, lactic acid and azelaic acid, as well as pigment-inhibiting ingredients, like tranexamic acid, hydroquinone, licorice root, kojic acid and alpha arbutin. It’s best to use a pigment-inhibitor twice a day. 

Professional treatments, such as lasers and peels, can also help both PIE and PIH.

How to prevent PIE and PIH

While often inevitable, there are some things you can do proactively to prevent both PIE and PIH or reduce their severity. Avoid picking, squeezing and popping, which can damage blood vessels underneath. Wear pimple patches or ice your skin to help resist the urge! 

As mentioned above, the first step of prevention begins with sunscreen. UV exposure can exacerbate the pigment-formation process, as well as irritate and inflame the skin. Make sure you’re wearing and reapplying sunscreen daily – yes, even in the winter, even in the rain. 

Physical Scarring

True acne scars are identified by textural changes in the skin. There are two types of physical acne scars: atrophic and hypertrophic. 


Atrophic, or intended scars are identified by depressions in the skin. There are 3 types – icepick, boxcar and rolling – which have to do with the shape and size of the scar. Atrophic scarring happens when inflammation causes a loss or change in tissue, or collagen.

Icepick scars are narrow and deep. They are the most common and often found on cheeks. Because of their depth, they are typically the most challenging to treat. 

Boxcar scars are wider than icepick scars and have steep, well defined edges. You might recognize boxcar scars as the type left behind from chicken pox! They are most often found where the skin is thicker, like the jaw line. 

Rolling scars can vary in size and have less defined edges than boxcar scars, resulting in a wavy, or “rolling” appearance. 


Hypertrophic scars are raised scars, caused by an overproduction of collagen. If the size of this scar is larger than the original acne that caused it, it is considered a keloid. These types of scars are most common on the body, especially the chest and back, though they can also form on the face. They’re also more common in medium to deep skin tones. 

Treating Physical Scarring

Many types of physical scarring can be effectively treated by a professional. Peels, lasers, subcision, microneedling and fillers are commonly used in-office. Depending on the treatment, you may need to wait until your active inflammatory acne is resolved to begin treating physical scarring. Talk to your esthetician or dermatologist to determine the best course of action for your skin. 

Outside of professional treatments, sunscreen is of the upmost importance to protect and preserve collagen, as well as to promote healing. Retinoids may also help with collagen production, though may not be enough depending on the severity of the scar. However, both sunscreen and retinoids can be used preventatively to help reduce the risk of scarring in the first place. And of course, remember not to pick!