Explainer · August 25, 2026 · 6 min · By Quentin Asare
Types of scarring from acne: a stretch-and-color key for naming what is on your face
Most people asking about types of scarring from acne are lumping together two things that are not scars at all and three that are, and the wrong label sends them to the wrong treatment. Here is a three-question key you can run with a mirror and two fingers, plus the awkward fact that the standard classification was never tested against a population before it became the standard.
The question people bring into a consult is almost never "what is the ice pick to boxcar ratio on my left cheek." It is "why does my skin still look like this," asked while pointing at a patch that might be a red stain, a brown stain, a pit, a trench or a lump. The reason the types of scarring from acne matter is not academic. Each one has a different cause inside the skin, a different natural history, and a completely different list of things that work on it. Get the name wrong and you can spend a year on a serum for a problem that needed a needle, or book resurfacing for a problem that would have faded on its own. This piece gives you a way to name what you are looking at, using a three-question key you can run tonight, and then explains where the official classification came from and what it leaves out.
The three-question key. Do this in front of a mirror with daylight or a lamp off to one side, not overhead bathroom lighting, which flattens everything. Question one is about color: put a finger on either side of the mark and press the surrounding skin so it blanches. If the mark itself fades to nearly nothing under pressure, you are looking at redness from dilated vessels, which is post-inflammatory erythema, not a scar. If it stays brown or gray under pressure, it is pigment, which is post-inflammatory hyperpigmentation, also not a scar. Question two is about surface: close your eyes and run a fingertip across the area. If you feel nothing and the mark is purely a color, stop here, because the piece on fading the dark marks acne leaves behind is the one you want. If you feel a dip, a hole or a bump, it is a true scar and you move to question three. Question three is the stretch: pull the skin taut between two fingers about an inch apart across the scar. A depression that disappears or nearly disappears when stretched is a rolling scar, meaning the surface is being pulled down by bands of fibrous tissue underneath and the skin itself is intact. A depression that stays exactly as sharp when stretched is either an ice pick, if it is narrower than about two millimeters and looks like a pinprick that goes deep, or a boxcar, if it is wider with a flat floor and vertical walls, like a small punch was taken out. A bump that rises above the skin is a hypertrophic or keloid scar, which is excess collagen rather than lost collagen, and belongs to a different treatment family entirely.
Why the stretch matters more than the name. The stretch test is the single most useful maneuver because it sorts scars by mechanism rather than by appearance. Rolling scars are a tethering problem. The epidermis is fine; something beneath it is holding it down. That is why they respond to subcision, where a needle is passed under the scar to cut the tethers, and why lasers that only resurface the top layer tend to disappoint on them. Ice pick and boxcar scars are a missing-tissue problem. Nothing is holding the skin down; a column or a block of dermis is simply gone, and the fix is either to fill it, lift it, excise it or resurface the shoulders so the edge is less visible. Once you know whether your scar is tethered or absent, the choice between what can and cannot be fixed stops being a menu and becomes a short list.
Where the categories came from. The names most clinics use, ice pick, boxcar and rolling, trace to a 2001 review by Jacob, Dover and Kaminer in the Journal of the American Academy of Dermatology that proposed a classification of atrophic acne scars based on width, depth and three-dimensional architecture. It was a sensible and durable scheme. It was also a proposal made in a review article, drawn from clinical observation rather than from a sample of patients whose scars were measured and sorted. A second system arrived in 2006, when Goodman and Baron published a qualitative global grading scale that scores severity from grade one, meaning flat marks of color only, to grade four, meaning scarring visible at a conversational distance that cannot be flattened by stretching. Notice that the stretch test is baked into the top of that scale. The two systems answer different questions. Jacob names the shape; Goodman grades how much it shows. A single face can carry a Goodman grade three with a mix of all three Jacob types, which is the normal situation rather than the exception.
What counts as a scar and what does not. The American Academy of Dermatology's overview of acne scar causes draws the same line the key above draws: scarring happens when inflammation destroys dermal tissue and the repair is either too little collagen, producing a depression, or too much, producing a raised scar. Color changes are the aftermath of inflammation without structural loss, and Mayo Clinic's acne overview lists them separately for that reason. The practical consequence is that a large share of what patients call scarring will improve with time and pigment-directed treatment, while true atrophic scars do not fade because there is nothing to fade; the tissue is absent. If you have been waiting for a pit to go away, the waiting is the problem.
What the studies do not tell you. Three gaps are worth naming. First, there is very little published data on how common each type is. The prevalence work that exists, such as a population study of eighteen-year-old males in Brazil, tells you what fraction of young people carry acne scars at all, but does not break the scars down into ice pick versus boxcar versus rolling, so nobody can honestly tell you whether your pattern is typical. Second, the classification systems were built mostly on lighter skin, and in deeper skin tones the pigment problem and the scar problem overlap so heavily that the color question in the key often has to be answered "both," which neither system handles cleanly. Third, no scheme includes a category for the mixed scar, the shallow boxcar with a tethered floor, that is arguably the most common thing a patient actually has. Clinicians treat those by mechanism anyway, which is another reason the stretch test travels better than the label.
How to use your answer. Write down what the key told you for each region of the face, because the regions usually differ. Cheeks tend toward rolling and boxcar; temples and the sides of the nose toward ice pick; the jawline toward hypertrophic in people who form thick scars. Bring that map to a consult and you will spend the appointment on sequencing instead of on naming. For scars that were tethered on the stretch, ask about subcision before anything else. For scars that held their shape, read which device suits which scar before booking a package. And if the key sent you back to color at question one, the plan is the same one that manages the acne itself, because active breakouts are still writing new marks; the clearskin guide to acne treatment covers how to stop the source while the old marks fade.