Understanding Hyperpigmentation

Skin pigmentation is a significant cosmetic problem related to melanin production, mainly resulting in skin pigmentation disorders. Melanin is a substance in the body that produces hair, eye and skin pigmentation and provides the natural colour of a person’s skin. An essential role of melanin is that it protects the cells in the skin from DNA damage by absorbing the sun’s ultraviolet rays (UVR).

Hyperpigmentation occurs when excess melanin causes a darkened appearance in small or large areas of the skin.

Types of skin pigmentation:

• Melasma – Caused by hormones and the endocrine system.
• Post-inflammatory hyperpigmentation (PIH) – Caused by trauma to the skin, burns, skin conditions such as acne or poorly performed aesthetic treatments.
• Age spots (Solar lentigo) – Caused by skin exposure to UVR, pollution and DNA damage.

UVA-induced hyperpigmentation

• Is caused by skin exposure to the UVR produced by the sun or sunbeds and results in freckles, age spots and uneven skin tone.

Post-inflammatory hyperpigmentation (PIH)

• Can be seen on skin areas exposed to trauma (e.g., acne spots, irritation, burns). Tissue trauma stimulates specific immune cells in the skin called Langerhans cells, which increase the activity of the melanocytes in the skin, causing increased pigment formation.

Melasma (chloasma)

• Represented by symmetrical patches on the skin, most predominantly seen on the cheeks, chin, upper lip and forehead. This type of pigmentation can be related to abnormal hormone production such as that seen in pregnancy, menopause, or patients using the birth control pill or hormone replacement therapy.

The hyperpigmentation process is shown below:

1. Hyperpigmentation triggers.

• Inflammation
• UV rays
• Hormones
• Skin trauma

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2. Melanin production.

• Melanin is produced inside the melanocytes with the help of an enzyme called Tyrosinase.

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3. Melanin is transferred to skin cells.

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4. The skin cells are in a constant process of moving towards the surface of the skin (natural skin exfoliation process).

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5. The skin cells containing melanin reach the skin’s surface, causing dark spots or dark areas.

Current treatments for hyperpigmentation

• Topical treatments

Topical treatments are first-line treatments for hyperpigmentation disorders. Topical agents such as hydroquinone, vitamin C or ascorbic acid, arbutin, niacinamide, glycolic acid, kojic acid and retinoids (i.e., Vitamin A, Retinol) are commonly used agents to combat and improve hyperpigmentation.

• Oral treatments

Oral agents are considered a second-line treatment for hyperpigmentation; Tranexamic acid is one of them.

• Chemical peels

Chemical peels can be used to improve hyperpigmentation. These treatments work by removing the superficial layer of the skin (i.e., stratum corneum). Peels can also enhance penetration of other topical agents when used together.

Although treatments to improve hyperpigmentation are effective, they are associated with side effects. Thus, prevention of hyperpigmentation and maintenance therapy with sunscreens for UV protection is crucial to prevent skin damage. 

Reference list

1. Nahhas, A.F., Abdel-Malek, Z.A., Kohli, I., Braunberger, T.L., Lim, H.W. & Hamzavi, I.H. (2018). The potential role of antioxidants in mitigating skin hyperpigmentation resulting from ultraviolet and visible light-induced oxidative stress. Potodermatol Photoimmunol, 35, 420-28.
2. Goswami, P. & Sharma, H.K. (2020). Skin hyperpigmentation disorders and use of herbal extracts: A review. Current Trends in Pharmaceutical Research, 7(2).
3. Nautiyal, A. & Wairkar, S. (2021). Management of hyperpigmentation: Current treatments and emerging therapies. Pigment Cell Melanoma Res, 34, 1000-14.