OVERVIEW

What are acne marks?

Acne marks are imprints left on the skin's surface after conditions like acne or dermatitis subside^[1]. They can be categorized into red acne marks and dark brown acne marks^[2].

• Red acne marks: These result from the dilation or proliferation of capillaries caused by various inflammatory mediators produced during the immune response in acne^[1].
• Dark brown acne marks: These are caused by excessive or abnormal distribution of melanin in the epidermis and/or dermis. Acne is the most common endogenous factor leading to dark brown acne marks. Acne scars, formed due to endocrine disorders during adolescence, have a high incidence rate^[3]. Over 90% of acne cases leave varying degrees of marks after healing, meaning that out of 100 recovered acne patients, 90 will have residual marks^[4].

SYMPTOMS

What are the manifestations of acne marks?

Acne marks are divided into red acne marks and dark brown acne marks.

• Red acne marks: Usually appear red. They are caused by the dilation and proliferation of epidermal capillaries due to stimulation by inflammatory factors^[1].
• Dark brown acne marks: Usually appear black or brown. They are caused by melanin deposition induced by inflammatory factors.

CAUSES

What are the common causes of acne marks?

Acne marks are a type of post-inflammatory hyperpigmentation, generally caused by inflammatory stimulation or skin trauma^[1].

Currently, the exact pathogenesis remains unclear. It may involve increased melanin production or abnormal distribution after inflammation^[5], with melanin being transferred to surrounding keratinocytes. Melanocytes may appear in the superficial dermis, leading to visible acne marks^[1].

Inflammatory mediators may stimulate melanocytes.

DIAGNOSIS

How to Diagnose Acne Scars?

The diagnosis of acne scars is usually straightforward and typically requires no special tests. It primarily involves visual inspection to assess the location, color (light brown, dark brown, red, etc.), extent, and severity of the scars. The diagnosis is based on the patient's history of conditions like acne or dermatitis, combined with the developmental characteristics of the scars. In some cases, a pathological examination may be performed to rule out other causes of pigmentation.

TREATMENT

When can acne scars be treated with medical aesthetics?

It is recommended to proceed when acne is completely stable and no longer recurring. If acne remains unstable, it may lead to more post-inflammatory erythema.

What is the cost of medical aesthetic treatments for acne scars?

Prices vary by hospital and are based on the treatment area. A single session can range from hundreds to thousands of yuan. While one treatment may show results, multiple sessions are usually needed for optimal effects.

How are acne scars treated?

There are various treatment options, including medication and physical therapies. Common methods include:

• Fractional laser therapy: This penetrates deeper into the skin than traditional lasers, reaching the dermis to promote blood circulation and scar tissue metabolism, effectively improving acne scars^[3].
• Red and blue light therapy: A painless, non-invasive treatment that reduces lesions, inhibits sebum breakdown, prevents recurrence, and minimizes inflammation, playing a key role in preventing acne scar relapse^[1].
• Collagen dressing: Contains amino acids and active collagen to accelerate epidermal cell growth and nourish skin cells, improving acne scars^[1].
• Topical hydroquinone: Reduces melanosome formation and pigmentation but is rarely used clinically due to its irritancy^[1].
• Topical retinoids: Effective for dark brown acne scars, though initial use may cause irritation. Retinoids inhibit acne bacteria, reduce inflammation^[2], and promote melanin dispersion. They are also commonly used to prevent microcomedones and maintain skin stability while reducing pigmentation^[2].
• Azelaic acid: Selectively inhibits abnormal melanocytes and has anti-proliferative effects. It is a gentler alternative for those intolerant to retinoids^[2].

• Chemical peels: Involves applying exfoliants (e.g., fruit acids) to the skin, effective for dark brown acne scars. Results are faster and more noticeable than topical treatments but must be performed by professionals^[6].
• IPL (Intense Pulsed Light) therapy: An effective method to treat acne scars by enhancing microcirculation, lightening pigmentation, and improving overall skin tone. It offers fast results, minimal pain, and low recurrence rates^[3], making it a great option for those with stable skin and sufficient budget.

Can acne scars fade on their own?

Most acne scars gradually fade within 3–6 months, with very few cases failing to resolve completely^[1]. Topical ointments like centella asiatica cream or mucopolysaccharide polysulfate cream (Hirudoid) may help newly formed scars.

However, for persistent post-inflammatory erythema lasting over 2–3 months or severe pigmentation, these treatments are unlikely to work, and further intervention is necessary^[1].

DIET & LIFESTYLE

Can people with acne scars eat soy sauce?

Currently, there is no clear research indicating that soy sauce may worsen acne scars.

What should acne scar patients pay attention to in their diet?

• Avoid spicy and irritating foods, and limit or avoid low-fat and skim milk. If you want to drink milk, consider unsweetened yogurt. If you must drink pure milk, opt for whole milk, with a daily intake not exceeding 700 mL.
• Reduce consumption of foods with added sugar.
• Eat more foods rich in vitamin A and vitamin B6, such as carrots, animal organs, spinach, soybeans, and whole grains.
• Consume zinc-rich foods like eggs, lean meat, and animal liver.
• Avoid excessive calorie intake and prevent obesity^[7].

What should acne scar patients pay attention to in daily life?

• Do not smoke^[2].
• Avoid prolonged sun exposure to prevent worsening skin pigmentation.
• Clean and moisturize facial skin properly. Use warm water and oil-control medical skincare products with a pH close to the skin’s to reduce oil buildup and clogged pores. Avoid oily cosmetics and corticosteroid products to restore the skin barrier^[7].
• Avoid squeezing, scratching, or other irritations^[7].
• Acne scars not only affect appearance but also have a significant psychological impact^[3]. Maintain a positive mood, avoid anxiety and low self-esteem, and relieve stress through music, movies, meditation, walks, etc., to build confidence in recovery.

PREVENTION

How to Prevent Acne Scars?

• Seek early treatment for acne (pimples) to prevent recurrence or worsening, which can lead to scarring.
• Avoid squeezing pimples with your hands to prevent pigmentation and worsening of acne scars^[6].
• UV rays are a major factor in melanin production, so always use sun protection when going outdoors to prevent pigmentation-related acne scars.
• Avoid excessive consumption of spicy, irritating, or greasy foods, and reduce intake of high-sugar and high-fat foods^[6]. Instead, eat more fresh vegetables, fruits, and vitamin-rich foods like spinach, oranges, and apples^[6] to regulate hormones and prevent acne and scarring.