Vitiligo is an autoimmune disease, which means it occurs when the immune system attacks the body’s own tissues and cells. Treatments that suppress this immune response may help slow depigmentation or restore skin color.
In vitiligo, the immune system attacks melanocytes — the cells that produce a pigment called melanin. Melanin is responsible for the skin, hair, and eye pigmentation.
If these cells become damaged, die, or stop producing melanin, it can lead to depigmentation of the skin, hair, and other body surfaces.
This article takes a closer look at the immune system’s role in vitiligo, including the development of the condition and how it affects treatment approaches.
“There is a complex relationship between melanocytes and the immune system,” said Dr. Ted Lain, a board certified dermatologist practicing in Austin, Texas. As a result, experts are still teasing apart the exact mechanisms of melanocyte destruction by immune cells.
- UV light from the sun
- chemicals in cosmetics and clothing
- infectious pathogens, such as viruses and bacteria
“Under stress, the melanocytes display signals that lead to immune system activation,” explained Lain. This activation leads to the recruitment of immune cells that help protect the skin against whatever causes stress.
However, if the melanocytes send out these stress signals too often or incorrectly, it can lead to a loss of regulation of these immune processes. “As the immune system gets further activated, melanocyte destruction ensues, resulting in the depigmentation associated with vitiligo,” Lain said.
Some experts believe that vitiligo occurs from genetic and environmental factors that lead to immune-mediated melanocyte destruction.
Vitiligo may affect about 0.5–1% of the population worldwide. People with a close blood relative who has vitiligo may be more likely to develop the condition, but it is not a guarantee.
Experts have identified changes in certain genes that affect the immune systems of people with vitiligo. But inheriting these changes does not guarantee a person will develop vitiligo. Instead, these changes may increase the risk that a second external event can trigger the development of the condition.
“Common trigger factors include stress, UV exposure, chemical exposure, and physical trauma,” explained Lain.
The American Academy of Dermatology notes that known triggers of vitiligo include:
- a severe sunburn
- a skin injury, such as a cut, scrape, or burn
- exposure to a strong chemical, such as phenol
Since vitiligo is a chronic and potentially progressive condition, continued or repeated exposure to these triggers can also lead to the expansion of existing vitiligo patches or the formation of new ones.
“We recommend that vitiligo patients do their best to avoid the triggers listed above,” said Lain. “That includes reducing stress, using sun protection, and preventing exposure to chemicals.”
There are many different types of treatment options for vitiligo. These include:
- Topical corticosteroids can help calm inflammation. Experts recommend them for short-term use due to the risk of potential side effects.
- Topical calcineurin inhibitors affect the immune system to help reduce inflammation. They may work best on small areas of depigmentation.
- Topical JAK inhibitors target specific immune pathways to help tame an overactive immune response. This may help prevent the destruction of melanocytes.
- Light therapy, also known as phototherapy, suppresses the immune system to help prevent melanocyte destruction. It may also help stimulate new melanocyte production, which can result in the appearance of new pigmentation in previously affected skin patches.
- Oral steroids may help slow the progression of vitiligo by suppressing the immune system.
“These vitiligo treatments focus on the immune system activation,” explained Lain. “They work to decrease [immune cell] activation and recruitment.”
Does the use of these treatments mean a person has a weakened immune system?
“We don’t consider the topical application of these medications, or the use of phototherapy, as medications that cause systemic immunosuppression,” said Lain. That is because these types of treatments only affect the local immune system where the person applies the topical treatment.
“However, sometimes we use pulse systemic steroids, which does cause [temporary] immunosuppression,” he added. Experts typically give people these medications for short periods [1–2 weeks], which can help minimize risks associated with immunosuppression.
Atypical activation of the immune system in people with vitiligo may lead to the development of other autoimmune disorders.
Approximately 15–25% of people with vitiligo have at least one other autoimmune disorder, the
- rheumatoid arthritis
- type 1 diabetes
- pernicious anemia
- Addison’s disease
- systemic lupus erythematosus
- celiac disease
- inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis
Researchers have also linked vitiligo to some types of cancers. People who have melanoma or non-Hodgkin’s lymphoma may be more likely to develop vitiligo than others. Development of vitiligo is also possible during treatment for melanoma and may be an indicator of improved responses to treatment.
Vitiligo is an autoimmune condition caused by genetic and environmental factors that lead to the immune system’s destruction of melanocytes. Current treatment options may prevent local immune system activation to avoid melanocyte destruction and slow or halt the condition’s progression.