Skin Hyperpigmentation: Types and Causes
I am a dermatologist in Miami Florida, so I see patients often with areas of hyperpigmentation. Most causes of abnormal dark skin can be treated with skin lighting skin care products. However you will get better results if you identify the cause of the skin hyperpigmentation. This blog will discuss the causes of the different types of skin hyperpigmentation disorders.
What is hyperpigmentation?
The definition of hyperpigmentation is an excess of pigment that leads to an uneven skin tone. Hyperpigmented skin is darker than surrounding areas of skin. Most types of hyperpigmentation are due to an excess of the skin pigment melanin. This occurs when the cells in the skin that make color- melanocytes- are activated to increase melanin pigment production. The production of pigment is dependent on an enzyme called tyrosinase.
What skin type is prone to hyperpigmentation?
Skin types that are quick to produce melanin are more likely to develop hyperpigmentation.
Darker skin tones, pregnant women, people on estrogen, and those exposed to heat and sun are more likely to hyperpigment.
These Skin Types are more prone to get hyperpigmentation:
- Fitzpatrick Skin Type 3
- Fitzpatrick Skin Type 4
- Fitzpatrick Skin Type 5
- Fitzpatrick Skin Type 6
- Baumann Skin Type 1
- Baumann Skin Type3
- Baumann Skin Type 5
- Baumann Skin Type 7,
- Baumann Skin Type 9
- Baumann Skin Type 11
- Baumann Skin Type 13
- Baumann Skin Type 15
Can white people get hyperpigmentation?
Light skin types can get an uneven skin tone, melasma and dark spots- especially when pregnant. This is so common in pregnancy that it is called the mask of pregnancy.
All skin colors and tons can get hyperpigmentation, but it is more likely in darker skin types and skin that tans easily. It is very uncommon in redheads who have a genetic defect that makes it difficult for them to make pigment.
What does hyperpigmentation look like?
Hyperpigmentation from melanin looks like dark spots patches on the skin that can be light brown, dark brown, grey or black.
It may be across the central face as seen in melasma, in the site of a previous pimple, or in an area of recent injury or sun exposure. Tanned skin is an example of hyperpigmentation. Brown or black birth marks are another example.
It causes an uneven skin tone. You can see how these patches look on lighter skin in the image below.
Many things can trigger hyperpigmentation but they all cause increased pigment by activating one of the melanin stimulating pathways. There are many different biologic processes that are so complex that entire books have been written on this topic. (6) Many of these pathways involve melanocyte stimulating hormone (MSH) which triggers the melanocyte to make melanin. One way (but not the only way) that MSH makes melanin is by activating the enzyme tyrosinase. These pathways that lead to skin darkening are turned on by many things that we are exposed to. Production of melanin is the body's way of protecting cellular DNA from UV radiation, so tanning is a protective mechanisms. It is much healthier to have darker skin and lowers your risk of skin cancer. However, when dyspigmentation occurs because the skin tone becomes uneven, the term hyperpigmentation is used.
Causes of hyperpigmentation include:
increase in melanin stimulating hormone
medications like blood pressure medications
repeated friction or scratching
What skin pigment causes hyperpigmentation?
Several pigments can make the skin darker.
Melanin is the most common pigment to cause hyperpigmentation. This pigment gives a red brown or brown black color to the skin that varies depending on the type of melanin. There are 2 types of melanin: eumelanin gives a brown or black color while pheomelanin gives skin a yellow or red color. It is eumelanin that is predominantly responsible for hyperpigmentation because it is the darker of the 2 types of melanin.
Hemosiderin gives the skin a purple hue. Bruises can cause hyperpigmentation due to deposition of hemosiderin which leaves a grey, blue-violet color on the skin. As hemosiderin breaks down into biliverdin and bilirubin the pigment changes from green to yellow. But in some cases, hemosiderin remains in the skin giving it a purplish hyperpigmentation. dark circles under the eyes are also believed to be due to deposition of hemosiderin.
Oral colloidal silver can leave a blue pigment in the skin. This is why you should never drink silver. This condition is called argyria.
Oral tetracycline is an antibiotic that cancan leave a dark blueish brown pigment on the skin.
Because melanin is by far the most common cause of hyperpigmentation, this blog will concentrate on the types of hyperpigmentation due to an excess amount of melanin.
What are the types of skin hyperpigmentation?
There are many different types of skin pigmentation. A suntan is the most common form of hyperpigmentation. The second most common for is post inflammatory hyperpigmentation that occurs from acne. There are 4 main types that are treated with skin care products:
Of these, melasma is the hardest type to treat because it is very difficult to get rid of and tends to recur. Treating melasma requires skin lightening skin care products, two skin care routines, lifestyle habit changes, and a maybe even a prescription pill for hyperpigmentation.
Hyperpigmentation vs melasma
Melasma is a type of hyperpigmentation, but not all types of hyperpigmentation are melasma. Hyperpigmentation on the face, arms or chest that does not burn or itch is a symptom of melasma.
Hyperpigmentation vs tanning
The word hyperpigmentation has the connotation of being abnormal and unwanted. Tanning is a protective mechanism that results in a darker skin color. In reality tanning is a form of hyperpigmentation but because hyper mean an "excess", we do not use the term hyperpigmentation when referring to tanning because most people do not complain that their skin is too tan.
Having a darker skin type such as Fitzpatrick 5 is also not considered hyperpigmentation because it is a normal state. You may call darker skin "melanized skin" but it is not correct to say hyperpigmented. Think of it this way- when the term "hyper" is used it implies a disorder, disease, or biologic dysfunction.
Why is it so hard to treat hyperpigmentation?
Hyperpigmentation can go away on its own; however, in many cases it requires treatment. If you change your habits, limit sun exposure, reduce inflammation, and add skin lightening ingredients to your skin care routine, the excess pigment will usually go away.
In some cases it is very hard to get rid of excess pigment. Lasers can treat hemosiderin in the skin and melanin, but if the laser causes inflammation, the melanin can return. It is very hard to get rid of melanin because it is the skin's way of protecting itself and it wants to hold onto the pigment. Remember- the reason that melanocytes produce pigment is to protect your skin from sun. Melanin reflects away the sun's harmful radiation, helping to prevent DNA damage and skin cancer. Your body has evolved to have this protective function.
Melanin and other pigments that are deeper in the skin are harder to remove than superficial pigments. When melanin is confined to the epidermis, it is easier to get rid of it with exfoliants. Melanin in the dermis is deeper and difficult to remove.
How to know if my hyperpigmentation is epidermal or dermal?
When melanin is deep in the dermis, it can take a skin care routine much longer to work.
There are 2 ways to tell:
- Visualizing the skin with a camera such as the Canfield Viia camera
- Shining black light on the skin which makes the melanin fluoresce.
Your dermatologist can use these technologies on your skin to tell you if your melanin is in the superficial epidermal layers or deeper in the dermis.
Hyperpigmentation Can Occur on Different Part of the Face and Body
Discoloration of the skin on the face is very common on the face because of sun exposure. When your face is darker than your body, it is most likely that something in your skin care is making you tan more in the sun. This is called being photosensitive.
The 3 most common causes of dark spots on the face are:
Spots from acne
If it does not improve, see your dermatologist because there are a few diseases like hemochromatosis and porphyria that can cause the face and neck to be darker than the rest of the body.
Discoloration on the neck is almost always caused by sun. The exception is acanthosis nigricans which has a velvety texture.
The other causes of a dark neck are:
Poikiloderma of Civatte
Phytophotodermatitis occurs when you touch your skin with fragrances or certain foods that make skin sun sensitive. The most common causes are perfumes, lime juice, celery and figs.
Is your skin darker on your back? This is usually caused by post inflammatory hyperpigmentation from acne, folliculitis, or a rash. Some people get an itchy spot on the upper back that gets dark from excessive scratching. You can treat this with a prescription steroid cream or a natural anti-inflammatory oil like argan oil or jojoba oil. Make sure you wear a shirt that has a UPF of 50+ when in the sun.
Darkness around the mouth occur when the perioral skin is irritated or inflamed.
The most common causes of dark skin around the mouth are:
melasma (upper lip)
perioral dermatitis (around the entire mouth)
Dark lips can be your normal skin color.
Lips have less natural sun protection than other skin because they do not make sebum. This makes them more likely to burn and develop increased pigmentation.
Choose a lip balm with SPF to treat lip darkening of the lip lines.
Hyperpigmentation on the upper lip is usually due to melasma. See hyperpigmentation around the mouth discussed above.
Dark spots on the forehead are almost always caused from sun exposure.
Make sure you are not forgetting to apply sunscreen to your forehead.
If SPF burns your eyes when you sweat, avoid the sunscreen ingredient avobenzone.
Sun exposure is not the only thing that causes darkness on leg skin; medications that make skin sun sensitive can also discoloration.
Other causes of dark leg pigmentation are:
heat and infrared light
This is why you may develop dark patches of skin in areas where you had eczema. Use an eczema cream that has barrier repair properties. Look for creams with the Maltese cross pattern for best results.
To treat dark patches from eczema, you need to:
When pimples heal they often leave behind dark pigment resulting in dark spots on the skin where a pimple was.
This occurs because Inflammation triggers the production of skin pigment.
There are many causes of hyperpigmentation. Most types of hyperpigmentation improve with skin lightening treatments.
You will get better results if you identify the cause of the excess pigment, avoid sun, and use the right treatments. It all starts with knowing your Baumann Skin Type. (there are 16!)
Best References and Scientific Publications about Hyperpigmentation:
- Gutierrez, D. Ch. 20 Skin Pigmentation Disorders in Baumann's Cosmetic Dermatology 3rd edition (McGraw Hill 2022)
- Baumann, L Ch. 14 Uneven Skin Tone in Baumann's Cosmetic Dermatology 3rd edition (McGraw Hill 2022)
- Baumann, L Ch. 32 and 33 in Baumann, L Cosmeceuticals and Cosmetic ingredients (McGraw Hill 2015)
- Hadley, M. E., Heward, C. B., Hruby, V. J., Sawyer, T. K., & Yang, Y. C. (1981). Biological actions of melanocyte-stimulating hormone. Peptides of the Pars Intermedia, 244.
- Choudhary, R., Sharma, A., Kumar, S., Upadhyay, R. C., Singh, S. V., & Mohanty, A. (2020). Role of alpha-melanocyte stimulating hormone (α-MSH) in modulating the molecular mechanism adopted by melanocytes of Bos indicus under UVR stress. Molecular and Cellular Biochemistry, 465(1), 141-153.
- Nordlund, J. J., Boissy, R. E., Hearing, V. J., King, R. A., Oetting, W. S., & Ortonne, J. P. (Eds.). (2008). The pigmentary system: physiology and pathophysiology. John Wiley & Sons.
- Barrientos N, Oritz-Frutos J, Gómez E, et al. Allergic contact dermatitis from a bleaching cream. Am J Contact Dermat. 2001;12:33.
- DeCaprio AP. The toxicology of hydroquinone—relevance to occupational and environmental exposure. Crit Rev Toxicol. 1999;29:283.
- Guevara IL, Pandya AG. Melasma treated with hydroquinone, tretinoin and a fluorinated steroid. Int J Dermatol. 2001;40:212.
- Nordlund JJ. Postinflammatory hyperpigmentation. Dermatol Clin. 1988;6:185.
Hyperpigmentation vs Melasma
Melasma is a form of hyperpigmentation. But not all hyperpigmentation is melasma.