Not all acne scars look or behave the same way, and telling them apart is the first step to understanding what your skin actually needs. The main types of acne scars are atrophic scars (ice pick, boxcar, and rolling), hypertrophic and keloid scars that sit raised above the skin, and post-inflammatory marks (dark spots and redness) that are technically discoloration rather than true scars. Each type forms differently and responds to different approaches.
This guide explains how to recognize each type and why it forms. It is informational only and not a substitute for a professional assessment. If scarring affects how you feel, a board-certified dermatologist can examine your skin in person and give advice tailored to you.
What Is an Acne Scar?
An acne scar is a lasting change in the skin’s texture or surface that remains after a breakout heals. True scarring happens when inflammation from a pimple, cyst, or nodule damages the deeper layer of skin (the dermis) and the body’s repair process produces either too little or too much collagen as it heals.
This is different from the flat dark or red marks many people see after a breakout fades. Those marks are pigment changes, not scars, and they often improve on their own over weeks to months. Understanding which one you have matters, because they are managed very differently.
The Two Main Categories of Acne Scars
Dermatologists generally sort true acne scars into two broad groups based on how the skin heals:
- Atrophic (depressed) scars form when the skin makes too little collagen during healing, leaving a small dip or indentation. These are the most common type from inflammatory acne.
- Hypertrophic and keloid (raised) scars form when the skin makes too much collagen, leaving a firm bump that sits above the surrounding skin. These are more common on the chest, shoulders, back, and jawline.
Most facial acne scarring falls into the atrophic group, which is why the three subtypes below get the most attention.
Ice Pick Scars
Ice pick scars are narrow, deep, V-shaped pits that look as if the skin was pierced by a fine, pointed tool. They are usually less than 2 millimeters wide at the surface but extend deep into the skin, which is what makes them stand out as small, sharp-edged holes.
Why Ice Pick Scars Form
These scars typically develop after deep, inflamed breakouts such as cysts or infected pores that destroy tissue all the way down. Because the damage is narrow but deep, the skin heals into a tight, column-like depression rather than a wide one. Ice pick scars are often the most stubborn type because surface treatments rarely reach their full depth.
Boxcar Scars
Boxcar scars are broad depressions with sharply defined, vertical edges, giving them a box-like or crater-like appearance. They are wider than ice pick scars and have a flat base, so they look more like a shallow square or oval indentation than a pinpoint hole.
Why Boxcar Scars Form
Boxcar scars appear when an inflammatory breakout destroys collagen over a wider area, causing the overlying skin to drop and form a depressed patch with steep sides. They commonly show up on the cheeks and temples, where the skin is thicker. Their depth varies, so some are shallow and respond more readily to resurfacing approaches, while deeper ones are harder to smooth.
Rolling Scars
Rolling scars are wide, shallow depressions with sloping, rounded edges that give the skin a wavy or uneven appearance. Unlike boxcar scars, they do not have sharp borders, so the skin seems to gently roll rather than drop into a defined pit.
Why Rolling Scars Form
Rolling scars develop when fibrous bands of tissue form between the skin’s surface and the deeper layers, tethering the skin down and pulling it into broad waves. They tend to become more noticeable with age as the skin loses some of its natural firmness. Because the cause is tethering beneath the surface, treatments for rolling scars often focus on releasing those bands.
Ice Pick vs Boxcar vs Rolling: Quick Comparison
Here is a side-by-side summary of the three atrophic scar types to help you tell them apart:
| Scar Type | Shape | Width & Depth | Edges | Common Areas |
|---|---|---|---|---|
| Ice pick | Narrow V-shaped pit | Narrow, deep | Sharp, pointed | Cheeks, forehead |
| Boxcar | Crater with flat base | Wider, shallow to medium | Steep, defined | Cheeks, temples |
| Rolling | Wavy depression | Wide, shallow | Sloping, rounded | Lower cheeks, jawline |
Many people have a mix of all three on the same face, which is completely normal. A dermatologist can identify exactly which types you have, since the right approach often depends on the combination present.
Raised Scars: Hypertrophic and Keloid
Hypertrophic and keloid scars are firm, raised scars caused by an overproduction of collagen during healing. Hypertrophic scars stay within the boundary of the original breakout, while keloid scars grow beyond it and can keep expanding over time.
These raised scars are less common on the face and tend to appear on the chest, back, shoulders, and along the jawline. People with deeper skin tones are more prone to keloids. Because raised scars behave differently from depressed ones, a professional assessment is especially helpful here before trying anything that might irritate the area.
Post-Inflammatory Marks vs True Scars
One of the most common points of confusion is mistaking flat marks for scars. There are two kinds of post-acne discoloration, and neither is a true scar:
- Post-inflammatory hyperpigmentation (PIH) shows up as flat brown, tan, or dark patches where a pimple used to be. It is caused by extra pigment and is more noticeable in deeper skin tones.
- Post-inflammatory erythema (PIE) shows up as flat pink, red, or purple marks caused by lingering blood vessel dilation. It is more visible in lighter skin tones.
The key difference is texture: run your finger over the area, and if the skin feels smooth and level, it is most likely a mark rather than a scar. These marks usually fade gradually on their own, and consistent sun protection can help them resolve faster. True scars, by contrast, involve a permanent change in texture you can feel.
What Can Make Acne Scarring Worse?
While some scarring is hard to avoid, a few everyday habits are widely understood to raise the risk:
- Picking or squeezing breakouts pushes inflammation deeper and increases the chance of a lasting scar.
- Skipping sun protection can darken both marks and scars, making them more noticeable and slower to fade.
- Leaving inflammatory acne untreated gives deep cysts and nodules more time to damage the skin underneath.
The single most effective way to prevent new scars is to treat active, inflammatory acne early. If over-the-counter products are not keeping breakouts under control, a dermatologist can recommend a plan suited to your skin.
When to See a Dermatologist
Acne scarring is common and nothing to be embarrassed about, but professional input is worth it if any of the following apply to you:
- You have deep, inflamed breakouts (cysts or nodules) that keep returning.
- Your scars are deepening or spreading rather than improving.
- You are considering a procedure and want to know which options suit your scar type and skin tone.
- The scarring is affecting your confidence or daily life.
A board-certified dermatologist can examine your skin in person, confirm which scar types you have, and explain realistic options. This article is for general education only and does not diagnose any condition or recommend a specific treatment.
Frequently Asked Questions
What are the main types of acne scars?
The main types are atrophic (depressed) scars, which include ice pick, boxcar, and rolling scars; hypertrophic and keloid (raised) scars; and post-inflammatory marks, which are flat discoloration rather than true scars. Atrophic scars are the most common type on the face.
How can I tell if I have a scar or just a dark mark?
Gently feel the area. If the skin is smooth and level with the surrounding surface, it is most likely a post-inflammatory mark that will fade over time. If you can feel a dent or a raised bump, it is more likely a true scar involving a change in texture.
Are ice pick scars the hardest type to treat?
Ice pick scars are often considered the most challenging because they are narrow but extend deep into the skin, so surface-level approaches rarely reach their full depth. The right option depends on the individual scar, which a dermatologist can assess in person.
Do acne scars ever fade on their own?
Flat post-inflammatory marks often fade gradually over weeks to months, especially with consistent sun protection. True scars that involve a change in skin texture, such as ice pick or boxcar scars, generally do not disappear on their own and tend to need professional treatment to improve.
Can I prevent acne scars?
You can lower your risk by treating inflammatory acne early, avoiding picking or squeezing breakouts, and protecting your skin from the sun. No habit guarantees scar-free healing, but these steps are widely recommended to reduce the chance of lasting scars.
Key Takeaways
Acne scars fall into a few clear categories: depressed atrophic scars (ice pick, boxcar, rolling), raised hypertrophic and keloid scars, and flat post-inflammatory marks that are not true scars. Telling them apart comes down to shape, depth, edges, and whether you can feel a change in texture. Because the right approach varies so much by type and by individual skin, the most reliable next step is a professional assessment from a board-certified dermatologist. Treat this guide as a starting point for understanding your skin, not as medical advice.
