Skin Pigmentation Disorders: Types, Laser and Care

Medical Encyclopaedia › Hyperpigmentation (short definition)

In brief: Pigmentation disorders are changes in skin colour due to too much or too little melanin, the brown pigment of the skin. The most common are hyperpigmentations such as age spots, melasma or dark spots after inflammation. Most are harmless but distress many of those affected. A specialist assessment before treatment is important, because skin cancer can also begin as a dark spot.

How do pigmentation disorders develop?

Melanin is produced by melanocytes in the epidermis and passed on to the surrounding skin cells. UV radiation, visible light, hormones, inflammation, injuries and certain medicines stimulate production. If the pigment lies mainly in the epidermis (epidermal), it usually responds better to treatment than pigment that has sunk into the dermis (dermal). In hypopigmentation, pigment is missing, for example because melanocytes have been destroyed, as in vitiligo.

Common forms

• Age spots (solar lentigines): sharply defined brown spots on sun-exposed areas such as the face and backs of the hands.
• Melasma: extensive, often symmetrical browning of the cheeks, forehead and upper lip, favoured by hormones (pregnancy, the pill), UV and visible light; strongly prone to relapse (more on melasma).
• Post-inflammatory hyperpigmentation: dark spots after acne, eczema, injuries or cosmetic treatments; especially in darker skin.
• Freckles and café-au-lait spots: constitutional, usually harmless.
• Hypopigmentation: for example vitiligo, fungal infections such as pityriasis versicolor, or light spots after inflammation.

Assessment before any treatment

Before treatment, a dermatologist should assess the spot with a dermatoscope, in melasma often supplemented by an examination with Wood’s light. Spots that change in shape, colour or size, have irregular borders or bleed must be examined for skin cancer. A laser must not “treat away” suspicious lesions such as lentigo maligna, because this can mask a precancerous condition.

Treatment without laser

The basis of any treatment is consistent sun protection with a high sun protection factor; in melasma, tinted preparations with iron oxides, which also block visible light, help. Topical lightening agents such as azelaic acid, niacinamide, tranexamic acid, vitamin C, arbutin or retinoids are used. The strongest classic agent, hydroquinone, is not permitted in cosmetics in the EU and is only available as a medically prescribed medicine, often in combination with a retinoid and a corticosteroid. Chemical peels, for example with glycolic acid, can dissolve superficial pigment. In severe melasma, tranexamic acid is sometimes also used as a tablet; this is an unlicensed use and requires an assessment of the risk of thrombosis.

Laser and light treatment

Pigment lasers emit very short, high-energy pulses of light that specifically heat and break up melanin; the fragments are broken down by the body or shed with small crusts. Q-switched lasers (for example Nd:YAG at 532 or 1064 nanometres, ruby or alexandrite lasers), picosecond lasers and fractional lasers are used. Intense pulsed light (IPL) is not a laser but is also used for age spots.

• Age spots often respond well after just one or two sessions.
• Melasma is difficult: lasers are only considered when creams and sun protection are not sufficient. The result often does not last, and too high-energy treatment can worsen melasma.
• Post-inflammatory hyperpigmentation often improves with time and sun protection; lasers are used cautiously.
• In vitiligo, no pigment laser is used; instead, among other things, an excimer laser with UV light is used to stimulate repigmentation.

In darker skin types (Fitzpatrick IV to VI), the risk of darkening or light spots is higher. Longer wavelengths, low energy and a test treatment on a small area reduce this risk.

Preparation before laser treatment

• consistently avoid sun, sunbeds and self-tanners for four weeks beforehand; SPF 50 daily
• pause irritating active ingredients such as retinoids, fruit acids and high-dose vitamin C a few days beforehand, as agreed
• state all medicines, especially photosensitising ones (for example some antibiotics) and isotretinoin
• if prone to cold sores, discuss preventive antiviral therapy before facial treatments
• with darker skin or melasma, sometimes pre-treatment with lightening creams

Aftercare

• cooling in the first hours, gentle cleansing without rubbing
• do not pick off crusts and scabs; they usually fall off by themselves after one to two weeks
• barrier-strengthening care, for example with ceramides or dexpanthenol; after ablative lasers, greasy wound care as instructed
• strict sun protection with SPF 50 for at least four to eight weeks, permanently in melasma
• no sauna, no sport with heavy sweating and no exfoliation for a few days
• only reintroduce active ingredients such as vitamin C, retinoids or acids once the skin has completely healed and is no longer red

Blisters, weeping areas, increasing pain or marked darkening after a few weeks should be checked by a doctor. A step-by-step guide to care and the role of vitamin C serums is provided in the article Lasering pigment spots: preparation, aftercare and vitamin C.

Risks and limits

Possible side effects are redness, swelling, crusting, temporary or permanent darkening (post-inflammatory hyperpigmentation), light spots and, rarely, scars and infections. In melasma in particular, relapses are common because the causes continue to act. No procedure can guarantee permanently spot-free skin. Treatments should be carried out by appropriately qualified doctors; in Germany, the Ordinance on Protection against the Harmful Effects of Non-Ionising Radiation (NiSV) regulates who may use lasers on the skin. Lightening creams from unsafe sources may contain mercury or strong corticosteroids and damage the skin.

Related terms in the encyclopaedia

Hyperpigmentation, Melasma, Melanocytes, Picosecond laser, Fractional laser, IPL, Azelaic acid, Tranexamic acid, Niacinamide, Vitamin C, Sun protection factor (SPF), Chemical peel, Skin type, Lentigo maligna, Vitiligo

Sources

• AWMF-S2k-Leitlinie Lasertherapie der Haut (Reg.-Nr. 013-095), Deutsche Dermatologische Gesellschaft, 2022
• Bundesamt für Strahlenschutz (BfS): Verordnung zum Schutz vor schädlichen Wirkungen nichtionisierender Strahlung bei der Anwendung am Menschen (NiSV) – Informationen zu Laser- und IPL-Anwendungen
• Verordnung (EG) Nr. 1223/2009 über kosmetische Mittel (Regelungen zu Hydrochinon)
• Laser therapy in the treatment of melasma: a systematic review and meta-analysis (PubMed-ID 35122202, 2022)
• Passeron T., Picardo M.: Melasma, a photoaging disorder. Pigment Cell Melanoma Res 2018

Note: This article is for general information and does not replace advice, diagnosis or treatment from a doctor, dentist or pharmacist. Last updated: October 2026.