Acne scarring: types of scar and the treatments used

Acne is a condition of the hair follicles and the oil glands attached to them. When a spot is deep and inflamed, the damage can reach the surrounding skin, and the body repairs it imperfectly. The NHS lists scars among the possible effects of acne, including shallow holes in the skin that it calls ice-pick or boxcar scars. NHS inform adds that any type of acne spot can lead to scarring, but it is more common when nodules and cysts burst and damage nearby skin.

That is why scarring tends to follow the more severe or longer-lasting forms of acne, and why dermatologists put so much weight on treating acne early and properly. The BAD states that effective acne treatment can prevent new spots forming and reduce scarring.

Not every mark left by acne is a scar in the strict sense. The BAD points out that acne can leave discolouration which may be red, darker than your usual skin colour (hyperpigmented) or lighter than your usual skin colour (hypopigmented). These changes are a different problem from a change in the skin surface, and they are described by the NHS for scars generally as ranging across pink, red, purple, white, brown or skin-coloured.

For marks that do change the surface of the skin, the NHS scar page describes the following patterns that are relevant to acne.

Scar treatment makes little sense while new spots are still forming, because fresh inflammation can leave fresh marks. The BAD says that most acne treatments take 2 to 4 months to produce their full effect, and that if over-the-counter products have not helped, it is advisable to see a healthcare professional. It lists topical treatments such as benzoyl peroxide, retinoids and azelaic acid, oral antibiotics, certain contraceptive pills, spironolactone and isotretinoin as the main categories of prescription care.

Isotretinoin is described by the BAD as highly effective for severe acne, prescribed only under the supervision of a dermatology healthcare professional, with most courses lasting around 6 months. It can harm an unborn child and reliable contraception is essential while taking it. The NHS says to see a GP if spots are deep, painful or causing scars, which is the point at which prescribed treatment is usually considered.

The advice that comes up repeatedly in NHS and BAD material is simple and mostly about what not to do.

• Do not pick or squeeze spots or try to clean out blackheads; NHS inform says this can cause permanent scarring.

• Do not scrub the skin; the NHS says it irritates the skin and can make acne worse.

• Wash with a gentle cleanser twice a day at most (NHS inform) and use non-comedogenic skincare and make-up (NHS).

• Protect healing marks from the sun: the NHS advises covering a scar when in the sun for at least 1 year and using sunscreen with SPF 30 or more on it.

• Give massage a cautious try only where the NHS suggests it: it recommends massaging a fully healed scar with a water-based cream for up to 10 minutes a few times a day. This advice is written for scars generally rather than for acne scars specifically.

The NHS says that treatment for scars aims to improve how a scar looks, and that depending on the type it may include silicone dressings or gels, steroid injections or cream, cryotherapy (freezing the scar), laser therapy and skin camouflage. Several of these suit raised scars better than indented ones: a steroid injection, for example, is aimed at lumps rather than pits.

For indented post-acne scars specifically, the BAD says laser resurfacing of facial skin is an established technique and that various other techniques may also be used to improve the appearance of acne scars. Neither source gives a ranking of techniques, and results depend on the scar type, skin tone and how long the acne has been controlled. That is the reason an in-person assessment by a dermatologist matters more than any list of procedures.

Skin camouflage is a non-invasive option the NHS describes: special creams and powders colour-matched to your skin by a trained professional, available on prescription or to buy. A GP can refer you, or you can refer yourself online.

The BAD says acne can significantly affect psychological wellbeing, with low self-esteem, lack of confidence, negative body image, anxiety and depression, and it notes that severe acne has been associated with suicidal behaviour. The NHS says a GP can refer you for talking therapy if a scar is affecting your mental health. If you feel low, hopeless or unsafe, tell a GP or call NHS 111; in an emergency call 999.

The NHS advises seeing a GP if a scar is painful or bothering you, and asking for an urgent GP appointment or help from NHS 111 if a scar is swollen or painful, feels warm to the touch or has pus coming out of it. For acne itself, it advises a GP visit if the spots are deep, painful or causing scars, or if there are signs of a skin infection such as hot, swollen and red skin, which can be harder to see on brown and black skin.

Treating active acne, assessing scars and arranging skin camouflage fall within NHS care. Many people who want procedures aimed purely at appearance look to private dermatology. If you go down that route, ask the clinician to name the type of scar they are treating, what a realistic improvement looks like, how many sessions are usually needed, what the risks are for your skin tone, and who you should contact if the skin reacts badly. Treatment of marks that are mostly colour change is a different conversation from treatment of deep pits.