Boxcar scars appear as craters in the skin and can develop as a result of acne or chickenpox. Treatments are available to reduce their appearance, such as dermarolling, microdermabrasion, and surgery.
Boxcar scars are also known as craters or pockmarks. While they are not physically harmful, they can cause distress and low self-esteem, particularly when they appear on the face.
This article looks at what boxcar scars are, why they form, and how to reduce their appearance.
Boxcar scars are a type of atrophic acne scar. An atrophic scar is a depressed scar that heals below the normal layer of skin tissue.
There are three main types of atrophic acne scars:
- boxcar scars, which look like round or oval craters in the skin
- ice pick scars, which are small, deep, narrow scars
- rolling scars, which form when bands of scar tissue grow under the skin, giving it an uneven appearance
Boxcar scars form when the skin tries to heal after an injury but does not produce enough collagen. Collagen is a substance that helps support the skin, so a lack of collagen causes pitting.
Any type of acne can cause boxcar scars. They sometimes develop following chickenpox, too. Some risk factors make acne scars more likely, such as:
- having severe or inflammatory acne (nodules and cysts)
- having untreated inflammatory acne for a long time
- popping or squeezing acne blemishes before they heal
- having relatives who are prone to acne scars
According to the American Academy of Dermatology (AAD), while genetics and other risk factors influence who will or will not develop acne scars, they are not a guarantee. It is not always clear why one person develops scars while another does not.
Boxcar scars will not heal on their own. However, they may fade over time.
Treatment for boxcar scars can reduce their appearance. Sometimes, though, very deep boxcar scars remain visible even after treatment.
There are a variety of ways to try to minimize the appearance of boxcar scars. The method a person chooses may depend on the depth and severity of the scars.
Dermarolling, or microneedling, involves rolling or pressing tiny needles over the skin in order to create small injuries. This stimulates collagen production, which can reduce the appearance of depressed scars.
A 2014 study found that acne scars improved in their appearance after
Dermarolling has few risks when performed safely. However, it takes time for collagen to form, so people may require 3-6 treatments.
Chemical peels involve a dermatologist applying acids to the top layer of skin to exfoliate it. This allows new skin cells to grow. It is a form of resurfacing treatment.
Chemical peels can cause side effects, such as pain, redness, or flaking. This is more likely with stronger acid solutions. People may need to follow a special skincare routine while undergoing treatment and wear SPF to prevent sun damage.
Dermabrasion and microdermabrasion are facial resurfacing techniques that involve removing the epidermis, or top layer of skin cells, to encourage new skin cells to grow.
A person can choose from:
- Microdermabrasion: People who are qualified to carry out cosmetic skin treatments can carry out this procedure, which involves removing the very top layer of skin cells.
- Dermabrasion: This is a stronger form of exfoliation and removes the entire top layer of the skin. Because of this, only medical professionals should perform dermabrasion.
Laser resurfacing is another type of skin resurfacing that can help minimize the appearance of mild to moderate boxcar scars. There are
- Ablative laser treatment: This is a laser treatment that involves removing a small patch of skin around the scar, leaving a new, smooth-looking area of skin in its place.
- Non-ablative laser treatment: In this treatment, lasers stimulate collagen production to help improve the appearance of the scar without removing any skin.
Ablative laser treatment can produce more drastic results, with significant improvements after only one treatment. However, there is also a higher risk for infection than non-ablative treatments.
Fillers are skin injections that contain substances to plump up the skin. Depending on the type of filler, it may contain collagen or fat from another part of the individual’s body.
Fillers can reduce pitting and even out the skin. However, most give temporary results, lasting between 6-18 months. Some types of filler are permanent.
Medical professionals can also remove acne scars surgically. This option is best for those with a small number of scars. There are two types of procedure:
- Punch excision: This involves removing individual scars, creating a new scar that is less obvious than the original. This is one way to reduce the appearance of deep boxcar scars.
- Subcision: During this procedure, a doctor inserts a needle under the skin and passes it in multiple directions, separating the scar tissue from the skin. The body then produces collagen as the skin heals. Subcision is better for shallower boxcar scars.
Some doctors also provide platelet-rich plasma (PRP) injections alongside subcision or microneedling treatment to enhance their effects.
A 2019 study suggests that over 2 years, the combination of subcision and PRP can improve scars by
Some people use dermarollers and dermastamps at home. However, it is important to be aware that home kits may carry some risks.
It can be difficult to sterilize dermaroller needles at home properly. If a person does not sterilize or change the needle head frequently enough, they may be at risk for infection.
The needles that come in home dermarolling kits are also shorter than the ones professionals use and penetrate the skin at an angle. This may mean they do not work as effectively as professional microneedling treatments.
An older article in the Journal of Cutaneous and Aesthetic Surgery recommends:
- choosing high-quality dermarollers or stamps with needles shorter than
0.15 millimetersin length
- sterilizing the device with hot water or a sterilizing product after use before leaving to dry
- using the roller up to twice per week
- replacing the needle head every 100 uses and disposing of the old one safely
Boxcar scars are not something that requires immediate medical attention, but they can have a significant impact on mental health. If that is the case, people should speak to a doctor or dermatologist about their options.
There are numerous ways to reduce the appearance of boxcar scars. Minor surgery may help reduce a small number of scars, while procedures such as peels, laser treatment, or dermarolling may reduce more widespread scars.
A dermatologist can discuss a person’s options and advise the most appropriate treatment for them.