What Causes Vitiligo?

Vitiligo is a skin condition that causes loss of skin pigmentation in areas around the body. The lightened lesions are called macules (if they’re smaller than 1 centimeter in width) or patches (if they’re larger than a centimeter). Macules or patches appear when melanocytes, the cells that produce melanin, die or stop functioning. Melanin is a natural pigment that gives the skin, hair, and eyes their color and protects the skin from the sun's ultraviolet (UV) rays.

Vitiligo can affect any part of the external area of the body, including the genitals, eyes, and inside of the mouth. Loss of pigmentation generally starts on the hands, feet, forearms, and face.

Researchers do not know the exact cause of vitiligo. However, they believe that stress and exposing the skin to chemicals might lead to depigmentation. 

Theories

People with vitiligo have areas of depigmented skin in various shapes and sizes. The exact cause of vitiligo is unknown. However, researchers have proposed different theories.

Autoimmune Disease

The American Academy of Dermatology Association considers vitiligo as an autoimmune disorder. An autoimmune disease is when your body recognizes its own healthy cells as harmful and attacks itself. In the case of vitiligo, your body is recognizing melanocytes as harmful. Macules and patches will spread and grow as your body continues to attack melanocytes.

Vitiligo is associated with other autoimmune conditions, including:

• Thyroid disease: A general medical condition that is characterized by your thyroid—the butterfly-shaped gland in the neck—producing too many or too few hormones. Doctors use the term hyperthyroidism to refer to overproduction, and hypothyroidism when your body does not make enough thyroid hormones.
• Addison's disease, also known as adrenal insufficiency: This is when the adrenal glands, the glands that sit above the kidneys, do not produce enough cortisol and aldosterone. Cortisol is a stress hormone as it controls metabolism and helps the body respond to stress and inflammation. Aldosterone regulates blood pressure and the levels of salt and water in your body.
• Pernicious anemia: This is a condition that keeps your body from absorbing vitamin B12, which can negatively affect the nervous system. Symptoms include vomiting, diarrhea, and shortness of breath, especially during exercise.
• Psoriasis: It is a skin condition that accelerates the growth cycle of skin cells. It causes noticeable symptoms, such as pitted nails, redness, dryness, and cracked skin. The skin may also itch or burn, especially on the knees, scalp, and palms.
• Type 1 diabetes: This is a condition characterized by the immune system attacking pancreas cells called islet cells, which produce insulin—a hormone that controls your blood sugar.

Stress

A 2020 study published in the National Library of Medicine found that patients with vitiligo had high levels of perceived stress compared to those without the condition.

In a 2022 study, the authors explain that stress may trigger the release of reactive oxygen species (ROS) by melanocytes. ROS is an unstable molecule that carries oxygen and can easily interact with other molecules inside the cell. If there is ROS buildup in the cell, this may damage the genetic material, or DNA, and destroy the cell.

Chemical exposure

A 2017 study showed that chemical exposure may cause vitiligo or chemical-induced vitiligo. This occurs when you use products containing harmful chemicals, such as hair dyes or skin-lightening creams. When these come into contact with your skin, they may lead to pigment cell death.

These are some of the chemicals mentioned in the study that may cause the skin to lose its color:

• Rhododendrol, which was found in a skin-lightening cream
• Phenol, found in detergents and cosmetic products
• Para-phenylenediamine (PPD), found in hair dyes
• 4-tert-butylcatechol (4-TBC), found in lubricating oils

Is Vitiligo Hereditary?

Sometimes, vitiligo can run in families. This can happen if you inherit the NLRP1 and PTPN22 genes and the genes experience variations. These genes are supposed to help manage inflammation and the immune system’s activity, but the variations can inhibit them from doing so. As a result, this can lead to vitiligo.

A family history of vitiligo can increase your overall risk of developing it. A 2020 review suggested that 20% of people with vitiligo have a first-degree relative with the same condition.

Who Gets Vitiligo?

Some people are more likely to develop vitiligo than others. Factors that contribute to risk include:

• Genetics: You’re more prone to developing non-segmental vitiligo if you have a close relative who has vitiligo or another autoimmune disorder, such as rheumatoid arthritis.
• Co-occurring conditions: About 15–25% of people with vitiligo have an autoimmune condition.
• Age: Vitiligo can occur at any age, but white patches usually appear before age 20.
• Sex assigned at birth: Vitiligo can develop in people of any gender. However, it is more common in people assigned female at birth.
• Geographic area: A 2016 study found a higher prevalence of vitiligo in people who live in Africa.

Risk Factors

Some factors can worsen vitiligo or make you more prone to developing it.

Tattoos

Although tattoos can add color to the skin (which some people have used to try to add pigment to areas affected by vitiligo), tattoos are open wounds. A wound can cause something called the Koebner phenomenon, which triggers new spots of vitiligo to develop where the wound is. The new patches may appear about 10 to 14 days after the tattoo.

If you have vitiligo and want to cover up your patches, using skin dyes or makeup that matches your skin's color is a safer option.

Cancer Treatment

Melanoma is a type of skin cancer that develops in the melanocytes. One treatment option for melanoma is called immunotherapy. Immunotherapy is a type of treatment that helps recognize cancer cells and destroy them. Sometimes, it also attacks healthy tissue, such as pigment cells, increasing your chance of developing vitiligo patches. 

Physical Trauma

Sunburns can worsen vitiligo. This is because depigmented skin may be more sensitive to UV rays.

It is essential—even if you don’t have vitiligo—to protect your skin from the sun. Use sunscreen and reapply it every two hours when you’re out. Choose broad-spectrum products with SPF 30 or higher, as they offer protection against UVA and UVB rays. 

Other risk factors include:

• Skin cuts
• Inflammation
• Other skin conditions, such as psoriasis and dermatitis

Psoriasis and vitiligo are correlated; if you have one, you are more likely to develop the other.

A Quick Review

Vitiligo is a skin condition that causes the skin to lose its pigment in patches that vary in size and shape. We do not know why people develop it, but researchers consider it an autoimmune disorder, as the immune system mistakenly kills pigment cells.

Vitiligo can affect anyone. It is more likely to occur in those who have thyroid disease, diabetes, or a family history of the same condition. Using products that contain harsh chemicals or receiving cancer treatment may also trigger or worsen vitiligo.