Boxcar scars are a type of acne scar that leads to rounded dents or craters in your skin. Because of this, boxcar scars take longer to go away than other acne scars. These scars aren’t dangerous, but some people don’t like how they look.
What Are Boxcar Scars?
A boxcar scar is a round or oval depression in your skin that’s left behind after certain forms of acne heal. Some boxcar scars can look red or dark brown, but others are the same color as the skin around them.
Boxcar scars are atrophic, a term that means the skin didn’t return to its previous condition after healing. Experts don’t know exactly why some people get atrophic scars and others don't. Some people seem to be more likely to get atrophic scars from even mild acne, but others may have raised (keloid) scars. Yet others tend to not scar at all.
Most boxcar scars are linked to cystic or nodule acne, in which hard and painful cysts form under the skin. It seems that when this type of acne heals, your skin has a harder time replacing collagen that was lost. Collagen is what makes your skin look “filled out,” so its loss leads to dents or depressions.
Treating Boxcar Scars
Boxcar scars usually won’t go away without medical treatment. There are several ways you can reduce the appearance of atrophic scars, including:
Microdermabrasion. This involves gently abrading, or removing, the very top layer of your skin where the cells are dead. It may encourage your skin to produce more collagen, but it is effective for only shallow scars.
Dermabrasion is a deeper form of the same treatment that removes the whole top layer of your skin, including skin cells that are still alive. It may help improve the appearance of scars, but it also makes your skin red, sore, and sensitive to the sun.
Chemical peels. These treatments use chemicals to strip the top layer of your skin to encourage healthy skin growth. Chemical peels can be superficial, medium, or deep, but most doctors recommend only superficial and medium treatments for acne scars. A chemical peel can lead to redness, pain, and flaking skin, especially if it’s not done by a trained doctor.
Microneedling. Like chemical peels and dermabrasion, microneedling damages the skin in the scar. The doctor will use a device with tiny needles to puncture the scarred skin. Your skin heals the damage and makes more collagen.
Fillers. A filler is an injection that literally fills out the indented part of the scar. You can get temporary, semi-permanent, or permanent fillers in a scar. Temporary fillers may help your body make more collagen in the area, so they can help improve the scar’s appearance beyond the few months they last.
Laser therapy. With this treatment, a doctor uses targeted pulses of light energy to encourage your skin to heal and make collagen. Ablative lasers damage the top layer of your skin in an effort to repair it. Though they have uncomfortable redness and itchiness as side effects, ablative lasers are some of the most effective acne scar treatments available. Non-ablative lasers are used to target areas below the top layer of skin. Non-ablative lasers have fewer side effects but are also less effective.
Punch excision. For small scars, punch excision can be used to remove the scar entirely. The scar is removed with a small device and then closed like a minor wound. This treatment works best for people with few scars that are relatively tiny.
Preventing Boxcar Scars
The easiest way to prevent boxcar scars is to treat cystic acne before it scars in the first place. The longer cystic acne goes untreated, the more likely it is to scar when it heals.
Unlike other forms of acne, cystic and nodular acne often need medical treatment beyond over-the-counter (OTC) solutions. Because these cysts and nodules form deep under your skin, OTC topical treatments don’t address the source of the problem.
Instead, talk to your doctor about treatment. They may suggest options like:
- Prescription-strength topical treatments to dry out the cysts
- Retinoids, or strong vitamin A derivatives, to unclog hair follicles
- Antibiotics to treat an overgrowth of acne-causing bacteria
Finally, avoid popping any type of acne. Popping a pimple turns it into an open wound instead of a closed bump. Open wounds are more likely to scar, especially if they’re larger.