Acne Scars and Dark Spots: Why They Happen and When to See a Doctor

Acne (acne vulgaris) is a common inflammatory skin condition. It can leave scars or dark spots, known medically as post-inflammatory hyperpigmentation (PIH), during active breakouts or after they heal. Early medical care may help reduce the chance of either.

What is acne and why does it appear?

Acne affects the pilosebaceous unit, the hair follicle and its oil gland. At puberty, rising hormones increase oil (sebum) production, skin cells build up inside pores, and inflammation follows. The result can be blackheads and whiteheads (comedones), papules (small inflamed bumps), or deeper pustules and nodules.

Acne is graded by severity as mild, moderate, or severe, and also by lesion type. This matters because the type and severity of a lesion are linked to how likely it is to leave a mark after healing.

What is the difference between a scar and a dark spot?

The difference is fundamental, even if both appear as marks:

• Scar: a change in the skin tissue itself. It may be atrophic (a depression below the skin surface) or, less commonly, raised. A scar is a change in texture and structure.
• Dark spot (PIH): a flat brown or grey patch that appears where inflammation was, without a change in skin texture. It is caused by excess melanin pigment produced in response to inflammation, and it is more noticeable in darker skin tones.

Telling them apart helps a doctor understand what happened in the skin, because each follows a different assessment path.

Who is more at risk of scarring and dark spots?

A retrospective cohort study of 417 acne patients at King Abdulaziz Medical City in Jeddah, published in 2025, looked at how common these two after-effects are. Among the analysed participants:

• 22.8% had scarring only.
• 22.3% had dark spots (PIH) only.
• 36.2% had both scarring and dark spots together (the largest group).
• Only 18.7% had neither.

More than eight in ten participants in that cohort were left with some kind of mark.

The study also noted several associations (which are not necessarily cause-and-effect):

• Papules: their presence was linked to a clearly higher chance of having both scarring and dark spots together.
• Duration and recurrence: people whose acne lasted longer or kept coming back were more likely to develop complications.
• Sex: dark spots were more common in women in this cohort, while scarring was seen at a higher rate in men.

The study additionally observed that some treatment options were statistically associated with different levels of risk within this specific cohort. These are research observations from a single setting; the right treatment choice remains with a dermatologist after examining the individual, and no general medication advice should be drawn from them.

Why does early medical care matter?

Untreated inflamed lesions can progress and raise the chance of leaving a scar. Controlling inflammation early and avoiding squeezing or scratching lesions may reduce the odds of a lasting mark. Doctors commonly link delays in starting effective care to a higher risk of scarring.

Seeing a doctor early allows the condition to be assessed and a plan to be tailored to the skin type and acne severity. Dark spots often fade slowly over time, whereas a scar is a structural change that is usually more persistent, so the two are managed differently.

How do I care for my skin in general?

There are safe, general practices dermatologists recommend:

• Avoid squeezing or picking lesions, which increases inflammation and the risk of a mark.
• Use sun protection consistently, since sun exposure can make dark spots more visible and longer-lasting.
• Treat the skin gently and do not scrub hard.
• Consult a dermatologist rather than trying a changing series of home remedies that may irritate the skin.

These general measures do not replace an individual assessment.

When should you see a doctor?

It is worth consulting a dermatologist when:

• Acne is moderate to severe, or there are inflamed papules and nodules.
• Depressed scars or dark spots are starting to appear where lesions were.
• Acne persists for a long time or keeps recurring despite home care.
• The appearance of the skin is causing distress that affects quality of life.

This content was medically reviewed by Dr. Abdulhadi Jfri — Dermatology, Avant Clinics. Review date: 16 July 2026.

Source: Study published in Clinical, Cosmetic and Investigational Dermatology, 2025 — DOI: 10.2147/CCID.S504281

Frequently asked questions

Do acne marks go away on their own?

Dark spots often fade slowly over months to years, especially with sun protection. Scars are a change in skin tissue and tend to be more persistent. A medical assessment helps identify the type of mark and its likely course.

What is the difference between a scar and a dark spot?

A scar is a change in skin texture and may be depressed, while a dark spot is flat pigmentation without a texture change, caused by excess melanin after inflammation.

Who is more prone to acne after-effects?

In a Saudi study of 417 patients, having papules and a longer or recurrent course of acne were linked to a higher chance of scarring and dark spots. Dark spots were more common in women and scarring in men within that cohort.

Does early care help reduce marks?

Clinical knowledge suggests that controlling inflammation early and not picking at lesions lowers the chance of a lasting mark. An early assessment does not promise a result, but it allows a suitable plan.

When should I see a dermatologist?

When acne is moderate to severe, scars or dark spots begin to appear, breakouts persist despite home care, or the skin's appearance is affecting your quality of life.