Hyperpigmentation is a common skin concern resulting from excessive production of pigment within the skin5,7,8. Our body produces pigment through a very complex process influenced by internal and external factors as a protective mechanism against UV light exposure. At times due to various triggers, this process becomes excessive resulting in hyperpigmentation3,6,7.
Pigment is formed within an organelle of the melanocyte called the melanosome, which resides at the bottom layer of the epidermis3,6,7. It relies upon an enzyme called tyrosinase, which is formed from the amino acid tyrosine, to facilitate its production3,6,8. Once synthesised, the melanosome containing the pigment is transferred to the keratinocyte (skin cell) where it stays until it naturally sheds during skin cell turnover6,8.
There are two types of pigment found within our skin: eumelanin (black/brown) and pheomelanin (yellow/red), and it is the eumelanin which is dark in colour that provides the pigmentation we see4,6,8. The more eumelanin that we have within our skin, the darker it will appear4,8.
There are many common forms of hyperpigmentation including and not restricted to the following.
Post Inflammatory Hyperpigmentation:
- Hyperpigmentation due to an excessive inflammatory response to trauma or injury stimulating melanin production
- Presents within the area that the trauma, injury or inflammation has occurred
- Commonly seen in darker skin types
- Examples of trauma or injury: acne lesions, burns, over treatment during light based therapy, eczema, dermatitis
- It worsens with excessive sun exposure
- May resolve on its own over months or years or may need treatment3,5,7,8
Periorbital Hyperpigmentation/Periorbital Melanosis:
- Appears as a darkening around the eye area which can increase with age
- Frequently seen in individuals of dark skin colour
- The exact cause is unknown3,4,8
Melasma:
- Most commonly presents in the face of women
- The exact cause is unknown
- Exacerbating factors include UV exposure, hormones, medications and pregnancy
- It may appear as light grey to dark brown patches of pigmentation with irregular borders
- It commonly presents bilaterally on the cheeks, forehead, upper lip, nose and jawline4,5,6,8
Ephelides (Freckles):
- Commonly seen in lighter skinned individuals as a result of sun exposure
- Appear as round, oval or irregular spots on the skin with well-defined borders that are 1-2mm in width
- Can be red, tan or dark brown in colour
- They occur on sun exposed areas of the body
- Numbers and colour can increase with continual sun exposure
- They may fade with discontinued sun exposure5,8
Solar Lentigines:
- Seen in >90% of the population of individuals aged 60 and above
- More common in lighter skinned individuals
- Can vary in colour from light tan to dark brown, and can be round, oval or irregularly shaped with well-defined borders
- They are larger than ephelides at 1-3cm width
- Occur on sun exposed areas of the body5,8
There are many sources that can trigger pigment formation including:
- Light exposure from UV, visible and infrared sources: stimulate pigment production and can also darken the already existing pigment
- Environmental pollutants and free radicals that lead to oxidative stress
- Hormones
- Pregnancy
- Medications: oral contraceptive pill, hormone replacement therapy, phototoxic drugs, anti-convulsants
- Phototoxic cosmetics
- Genetics
- Trauma and injury
- Skin diseases such as acne, eczema, psoriasis and dermatitis4,6,8
Treatment of hyperpigmentation poses a challenge as there may be many influences, that can provoke its development3,8. The pigment itself may also be deposited in different areas of the skin with more superficial pigment being easier to address and deeper pigment being more challenging3,6. Due to this reason, it is suggested to address the hyperpigmentation from many angles including the elimination of trigger factors such as UV exposure, using sun protection strategies and using topical or physical treatments3,8.
As light exposure has the capacity to induce pigment production, it is essential to use a sunscreen on a daily basis4,8. A broad spectrum sunscreen is best, protecting from both UVA and UVB sources of light, with an SPF of at least 304,8. Sunscreens containing titanium dioxide and zinc oxide tend to be best tolerated by most people, and they provide a physical block against UV sources4,8. The use of sunscreens must always be supported with avoiding sun exposure and wearing sun protective clothing, sunglasses and hats4.
Cosmetic camouflage is beneficial for people who are wishing to cover the areas of hyperpigmentation, and can also double as a sunblock for extra sun protection8.
There are many cosmeceutical ingredients that have the ability to reduce the appearance of hyperpigmentation through a variety of mechanisms such as vitamin A, vitamin C, soy bean extracts, kojic acid, niacinamide, licorice plant extracts, resveratrol, lactic acid, salicylic acid and glycolic acid 3,4,5,8. Some of the mechanisms with which they work include:
- Increasing skin cell turnover through exfoliation to reduce the amount of melanin in the skin
- Blocking or reducing the formation of melanin
- Blocking the enzyme tyrosinase which is essential for melanin formation
- Preventing the transfer of the melanosome into the keratinocyte
- Reducing or preventing the darkening of skin pigment via antioxidant activity
- Acting as anti-inflammatory agents to reduce inflammatory derived pigment formation
- Affecting the melanocyte to reduce pigment formation3,4,5,8
It is common for cosmeceutical formulations to contain a combination of ingredients to assist with addressing pigmentation concerns from many angles for a more beneficial result8. Their use must be ongoing to maintain an effect5.
Physical treatment that may benefit pigmentation include chemical peels, microdermabrasion and laser therapy4,8. Skin needling has also been proven through research to reduce the appearance and subsequent relapse of melasma3,4.
It is important to note that undiagnosed hyperpigmented lesions should be assessed by a medical practitioner to rule out the formation of a malignant skin lesion5.
1Lima, E.A. (2015). Microneedling in facial recalcitrant melasma: report of a series of 22 cases. Anais Brasileiros de Dermatologia, 90(6), 919-921. doi: 10.1590/abd1806-4841.20154748
2Lima, E.V.A., Lima, M.M., Paixao, M.P., & Miot, H.A. (2017). Assessment of the effects of skin microneedling as adjuvant therapy for facial melasma: a pilot study. BMC Dermatology. 17(1), 1-6. doi: 10.1186/s12895-017-0066-5
3Nieuweboer-Krobotova, L. (2013). Hyperpigmentation: types, diagnostics and targeted treatment options. Journal of the European Academy of Dermatology and Venereology, 27(Supp. 1), 2-4. doi: 10.1111/jdv.12048
4Nouveau, S., Agrawal, D., Kohli, M., Bernerd, F., Misra, N., & Nayak, C. S. (2016). Skin hyperpigmentation in the Indian population insights and best practice. Indian Journal of Dermatology, 61(5), 487-495. doi: 10.4103/0019-5154.190103
5Plensdorf, S., Livieratos, M., & Dada, N. (2017). Pigmentation disorders: diagnosis and management. American Family Physician, 96(12), 797-804.
6Serre, C., Busuttil, V., & Botto, J.-M. (2018). Intrinsic and extrinsic regulation of human skin melanogenesis and pigmentation. International Journal of Cosmetic Science, (2018), 1-20. doi: 10.1111/ics.12466
7Taylor, A., Pawaskar, M., Taylor, S. L., Balkrishnan, R., & Feldman, S. R. (2008). Prevalence of pigmentary disorders and their impact on quality of life: a prospective cohort study. Journal of Cosmetic Dermatology, 7(3), 164-168. doi: 10.1111/j.1473-2165.2008.00384.x
8Vashi, N. A., & Kundu, R. V. (2013). Facial hyperpigmentation: causes and treatment. British Journal of Dermatology, 169(Supp. 3), 41-56. doi: 10.1111/bjd.12536