Hyperpigmentation Causes: Common Causes, Medical Conditions, and More

• There are several types and causes of hyperpigmentation, with exposure to the sun being the most common factor
• People with darker skin are most affected by hyperpigmentation
• Different skin types require different hyperpigmentation treatments
• Natural aging as well as some serious medical conditions can result in dark patches forming on the skin

What is Hyperpigmentation?

Hyperpigmentation is the term used to describe when the body overproduces melanin, which results in portions of the skin appearing darker than the affected person’s natural skin tone. 

Hyperpigmentation can appear on any part of the body but most typically develops on the face, neck, shoulders and hands.

There are different types of hyperpigmentation, with the most common being melasma, solar lentigo, and post-inflammatory hyperpigmentation.

Melasma

Melasma is usually brought on by hormonal changes and much more common to women than men, pregnant women in particular. It can appear on the stomach and/or cause dark symmetrical patches on the face, creating what can be described as a racoon-like mask around the eyes and mouth.

Post-inflammatory hyperpigmentation (PIH)

Post-inflammatory (PIH) refers to the darkening of the skin following a surface injury, often the result of acne, psoriasis, burns, or chemical peels.

Solar lentigo (sunspots)

Solar lentigo results from unprotected exposure to the sun’s UV rays and appears on areas of the body most frequently exposed to the sun; the face, hands, arms, and shoulders.

Common Causes of Hyperpigmentation 

Several factors contribute to hyperpigmentation, with the most common being:       

Sun exposure 

The sun is by far the most common cause of hyperpigmentation. When ultraviolet rays enter the skin, the body responds by producing more melanin to protect it from damage. People with darker shades of skin are most prone to hyperpigmentation resulting from sun exposure, which can damage skin both on the surface and at a cellular level. This type of hyperpigmentation, solar lentigo, creates dark patches known as solar lentigines, which occur more frequently as the skin ages. 

Acne

Acne-related hyperpigmentation results when dark patches of skin form over acne blemishes once they’ve healed, a condition formally known as post-inflammatory hyperpigmentation (PIH). These dark patches appear because the body’s natural reaction to skin inflammation is to produce more melanin. While it can happen to anyone, PIH tends to be more prevalent among people with darker skin tones.

Hormonal fluctuations 

Hormonal changes can lead to a type of hyperpigmentation called melasma. Melasma is believed to occur when elevated levels of the hormones estrogen and progesterone stimulate the overproduction of melanin, with the resulting hyperpigmentation made worse when unprotected skin is exposed to the sun.

Medications (MIP)

Hyperpigmentation can be caused by several different medications including: antibiotic, antimalarial, antiarrhythmic, antipsychotic and antiseizure drugs, as well as some cancer chemotherapies and certain acne and psoriasis preparations. This type of hyperpigmentation is called Medication-induced cutaneous pigmentation (MIP) and is believed to be due to the accumulation of heavy metals or drug-pigment complexes within the skin, stimulating the pigment cells to overproduce melanin.

Medical Conditions That Cause Hyperpigmentation

Hyperpigmentation can be brought on by a variety of medical conditions, including:

Addison’s disease

Hyperpigmentation is one of the first signs of Addison’s disease and usually develops in areas of the skin that are most frequently exposed to direct sunlight. Another sign of Addison’s disease can be the presence of black freckles on the forehead, face, and/or shoulders.

As Addison’s disease develops the adrenal glands gradually produce less cortisol and aldosterone, which leads the pituitary gland to overcompensate by making more melanocyte-stimulating hormone (MSH). This overstimulation of melanocytes leads to an increase in melanin production, which results in a darkening of the skin.

Hemochromatosis

Hemochromatosis is a genetic iron-storage disease that causes the body to absorb too much iron from food. Excess iron accumulation promotes oxidation and an increase in melanocytes, which causes a specific hyperpigmentation that’s defined by a bluish-gray or bronze tint.

Melasma

Melasma may possibly be a genetic condition and tends to be more common among women with darker skin. It often appears on the face and is triggered by a change in hormone production, such as when a woman becomes pregnant or starts taking birth control pills.

Hyperthyroidism

Hyperthyroidism can cause a pattern of hyperpigmentation similar to that of Addison’s disease, especially in patients with darker complexions. Overactivity or underactivity of the thyroid gland can result in hyperpigmentation due to the abnormal level of thyroid hormones in the body, which is characteristic of the condition.  

Natural aging

As we age our bodies go through a process called cellular senescence, which can lead to potential irregularities in melanin formation and immune response, both of which can lead to hyperpigmentation.

Causes of Hyperpigmentation in Dark and Light Skin 

People with Fitzpatrick skin types 5 and 6 are more likely to suffer from wound trauma pigmentation and hormonal pigmentation issues. For example, for people with these darker skin types, scarring usually results in the area of hyperpigmentation while trauma is more likely to result in hypopigmentation than it might among people who register lower on the Fitzpatrick scale.

People with darker skin are naturally more prone to hyperpigmentation in general. This is because their bodies already produce a high amount of melanin, which is what makes their skin dark in the first place. When hormonal factors or trauma trigger an increase in melanin production, they become more susceptible to developing dark spots than people with lighter skin tones.

One exception to this rule, however, concerns solar lentigo.

While people with lighter skin tones are at a reduced risk of overproducing melanin, they’re also more liable to experience hyperpigmentation resulting from sun damage.

Best Treatments for Hyperpigmentation  

There are a myriad of ways to reduce hyperpigmentation, with some approaches being more intense than others based on skin tone and the specific type of hyperpigmentation being treated. Some forms of hyperpigmentation, such as melasma, often eventually fade naturally, without need for treatment. However, depending on one’s skin tone, the process can be expedited by any of the following methods.

Skin lightening creams

Skin lightening creams and gels are available both over-the-counter and by prescription and typically contain a lightening agent such as hydroquinone, niacinamide, N-acetylglucosamine and/or licorice extract.  While it takes longer to lighten dark patches of skin with these products than it does through a professional treatment like dermabrasion or IPL therapy, they’re safe and effective for most skin types and work best on melasma and solar lentigines. Hydroquinone may not be suitable for dark-skinned individuals who register five and six on the Fitzpatrick scale as it could potentially cause too much trauma to the skin, worsening hyperpigmentation. 

Chemical peel

Chemical peels employ acids to reduce hyperpigmentation by removing the epidermis, and when applied in stronger concentrations, the middle layers of skin under where dark patches have appeared. Some chemical peels are available over-the-counter, but professional in-office treatments will provide the most immediate and pronounced results.

Chemical peels tend to work best for people with lighter skin tones and can be applied to all types of hyperpigmentation, with melasma and sunspots being the most receptive to the treatments

Laser peel

There are two kinds of lasers used to treat hyperpigmentation: ablative and non-ablative lasers.

Laser peel treatments work by directing beams of light on to the skin.

Ablative lasers remove the top layers of the skin and are the most intense variety of laser treatment used for this purpose. 

Non-ablative laser treatments also remove the top layers of skin, and like ablative lasers, promote skin tightening and collagen production when new skin cells grow to replace them.

Ablative lasers are most suitable for people with lighter skin tones. For those with medium to dark skin tones, non-ablative laser treatments may cause their skin to darken, and as such should be avoided.

Dermabrasion

Dermabrasion is a professional procedure that can be used to lighten post-inflammatory hyperpigmentation but is only risk-free for people who have light skin. For people with darker skin, the procedure could potentially result in scarring or increased pigmentation. 

With dermabrasion, a doctor uses a specialized tool to remove old skin and enable a new, smoother layer of skin to replace it, effectively lightening hyperpigmentation resulting from acne scars and other causes of surface discoloration.

Microdermabrasion

Microdermabrasion is a similar process to dermabrasion but is a less aggressive treatment suitable for all skin types and colors. 

With microdermabrasion a plastic surgeon or dermatologist sprays tiny exfoliating crystals on to the skin and then removes them with a specialized hand-held tool, eliminating the surface layers of the epidermis. The new skin that grows in to replace it should be smoother and less pigmented. Microdermabrasion is only effective on surface scars and multiple sessions are typically required.

Takeaway

Many factors can lead to dark patches forming on the skin. Some forms of hyperpigmentation, such as melasma, will eventually fade on their own naturally, while others may require professional treatment. People whose skin tone’s rate high on the Fitzpatrick scale are the most susceptible to hyperpigmentation and also have the fewest treatment options available to them. That said, hyperpigmentation is treatable for all skin types and colors.