The causes of vitiligo remain partly unknown, but research points to a combination of genetic, immune, and environmental factors

Vitiligo happens when the cells that make skin pigment (melanocytes) stop working or die. Why this occurs is not fully understood, but the evidence suggests it is not a single cause. Instead, most people with vitiligo have a mix of inherited susceptibility, an immune system that attacks pigment cells, and sometimes a triggering event—a burn, cut, or period of stress—that sets the process in motion. The condition is not contagious and does not spread from person to person.

The exact trigger varies from person to person. Some people develop vitiligo after a skin injury. Others notice it appearing during a time of emotional stress. Still others have a family history of the condition and seem to develop it without an obvious trigger. This variation is why vitiligo is so difficult to predict and why two people with the condition may have completely different stories about how it began.

Key Takeaways

  • Vitiligo appears to require both a genetic predisposition and an immune system response that targets melanocytes, the cells that produce skin color.
  • Physical trauma to the skin—cuts, burns, or surgical scars—can trigger vitiligo in people who are genetically susceptible, sometimes weeks or months after the injury.
  • Emotional stress, severe illness, and certain medications have been reported to precede vitiligo onset in some people, though the connection is not fully proven.
  • Sun exposure and chemical exposure may worsen existing vitiligo or trigger new patches in people at risk, but neither causes vitiligo on its own.

Genetic susceptibility: why some families are more affected

If a parent or sibling has vitiligo, your risk of developing it is higher than the general population, but it is not certain. Studies of families with vitiligo show that multiple genes are involved, not just one. This means the condition does not follow a simple inheritance pattern—you can inherit the genes that make vitiligo possible without ever developing it.

Researchers have identified several genes associated with vitiligo, many of them involved in immune regulation. Having these genes does not mean you will develop vitiligo. Instead, they appear to set the stage, making your immune system more likely to attack melanocytes under the right circumstances. This is why some people with a strong family history never develop the condition, while others without any family history do.

Immune system dysfunction: the primary mechanism

The most widely accepted explanation for vitiligo is that the immune system mistakenly attacks melanocytes. In people with vitiligo, white blood cells called T cells infiltrate the skin and destroy the pigment-producing cells. This autoimmune process is similar to what happens in other conditions like thyroid disease or lupus, where the immune system targets the body's own tissues.

Why the immune system turns against melanocytes in some people and not others is still being studied. One theory is that melanocytes in people with vitiligo may look "foreign" to the immune system, triggering an attack. Another is that the immune system's normal brakes—the mechanisms that prevent it from attacking healthy cells—are faulty. A third possibility is that melanocytes in people with vitiligo are more fragile and break down more easily, releasing substances that alert the immune system.

People with vitiligo are more likely to have other autoimmune conditions, such as thyroid disease, type 1 diabetes, or alopecia areata. This overlap suggests a shared underlying immune dysfunction rather than separate, unrelated conditions.

Physical injury and the Koebner response

A significant number of people with vitiligo report that the condition appeared or worsened after a skin injury. This pattern is called the Koebner response—the tendency for new skin lesions to develop at sites of trauma. The trauma can be a cut, burn, surgical scar, tattoo, or even vigorous scratching.

The Koebner response does not happen in everyone with vitiligo, and it does not happen every time someone with vitiligo is injured. But in people who are genetically susceptible and have the immune dysfunction underlying vitiligo, an injury may be the event that tips the balance and triggers visible depigmentation. The new patches can appear weeks or months after the injury, making the connection easy to miss.

This is one reason dermatologists recommend that people with vitiligo avoid unnecessary skin procedures and be cautious with activities that risk injury. It is also why some people notice vitiligo spreading along areas of friction—where clothing rubs, or where they habitually scratch.

Stress, illness, and other reported triggers

Many people with vitiligo report that the condition started or worsened during a period of emotional stress. While the connection is widely reported, the scientific evidence is mixed. Some studies show a link between stress and vitiligo onset, while others do not find a clear relationship. The difficulty is that stress is hard to measure objectively, and people may remember stress differently depending on when they are asked about it.

A plausible mechanism exists: stress hormones like cortisol can affect immune function, and chronic stress is known to worsen several autoimmune conditions. But whether stress is a direct trigger for vitiligo or simply a factor that worsens an existing condition remains unclear.

Severe infections and certain medications have also been reported to precede vitiligo onset in some people. Beta-blockers (used for high blood pressure), NSAIDs (like ibuprofen), and antimalarial drugs are among the medications occasionally linked to vitiligo. Again, the evidence is not conclusive, and most people taking these medications do not develop vitiligo. If you are concerned about a medication you are taking, discuss it with your doctor rather than stopping on your own.

Sun exposure and chemical triggers

Sun exposure does not cause vitiligo, but it can make the condition more noticeable. When skin tans, the contrast between pigmented and depigmented areas becomes sharper. Additionally, sunburn can trigger the Koebner response in people with vitiligo, leading to new patches at the site of the burn.

Certain chemicals have been associated with vitiligo-like depigmentation, particularly in people exposed occupationally. Phenolic compounds, used in some manufacturing and disinfection processes, have been linked to depigmentation in workers. However, this is different from typical vitiligo and appears to require both genetic susceptibility and significant chemical exposure. For most people, everyday exposure to common chemicals does not trigger vitiligo.

Why vitiligo is unpredictable

The reason vitiligo is so difficult to predict is that it requires multiple factors to align. You need genetic susceptibility, an immune system primed to attack melanocytes, and often some kind of trigger—but not everyone with all three factors develops the condition, and some people develop it without an obvious trigger at all.

This unpredictability also means that avoiding a suspected trigger may not prevent vitiligo if the underlying genetic and immune factors are present. Conversely, someone with a family history may never develop the condition despite having the genes. Understanding that vitiligo is multifactorial helps explain why it is so variable from person to person and why prevention strategies are limited.

Frequently Asked Questions

Can stress alone cause vitiligo?

Stress is reported by many people as a trigger, but it is not proven to cause vitiligo on its own. Stress may worsen the condition in people who already have the genetic and immune factors in place, but most people under stress do not develop vitiligo. If you are concerned about stress and your skin, managing stress through exercise, sleep, or counseling may help, but it is not a may provide prevention.

If my parent has vitiligo, will I definitely get it?

No. Having a parent with vitiligo increases your risk, but inheritance is not straightforward. Multiple genes are involved, and having the genes does not may provide you will develop the condition. Many people with a family history of vitiligo never develop it themselves.

Can an injury cause vitiligo years later?

Yes, in some people. The Koebner response can occur weeks or months after an injury, making the connection less obvious. If you have a family history of vitiligo or other signs of autoimmune disease, it is worth mentioning past injuries to your doctor when discussing new skin changes.

Does sunscreen prevent vitiligo?

Sunscreen does not prevent vitiligo, but it is still important. Sunscreen protects depigmented areas from burning, which can trigger the Koebner response and worsen the condition. It also reduces the contrast between pigmented and depigmented skin, making vitiligo less noticeable.

Are there foods or supplements that trigger vitiligo?

No specific food or supplement has been proven to cause vitiligo. Some people report that certain foods seem to worsen their condition, but this is not supported by strong scientific evidence. If you notice a pattern with a particular food, you can avoid it, but dietary changes alone are unlikely to prevent or reverse vitiligo.