What causes vitiligo?
Vitiligo is caused by the lack of a pigment called melanin in the skin. Melanin is produced by skin cells called melanocytes, and it gives your skin its colour.
In vitiligo, there aren't enough working melanocytes to produce enough melanin in your skin. This causes white patches to develop on your skin or hair. It's not clear exactly why the melanocytes disappear from the affected areas of skin.
Autoimmune conditions
Non-segmental vitiligo (the most common type) is thought to be an autoimmune condition.
In autoimmune conditions, the immune system doesn't work properly. Instead of attacking foreign cells, such as viruses, your immune system attacks your body's healthy cells and tissue.
If you have non-segmental vitiligo, your immune system destroys the melanocyte skin cells that make melanin.
Vitiligo is also associated with other autoimmune conditions, such as hyperthyroidism (an overactive thyroid gland), but not everyone with vitiligo will develop these conditions.
Risk factors
You may be at increased risk of developing non-segmental vitiligo if:
- other members of your family have it
- there's a family history of other autoimmune conditions – for example, if one of your parents has pernicious anaemia (an autoimmune condition that affects the stomach)
- you have another autoimmune condition
- you have melanoma (a type of skin cancer) or cutaneous T-cell lymphoma (cancer of the lymphatic system)
- you have particular changes in your genes that are known to be linked to non-segmental vitiligo
Neurochemicals
Segmental vitiligo (the less common type) is thought to be caused by chemicals released from the nerve endings in your skin. These chemicals are poisonous to the melanocyte skin cells.
Triggers
It's possible that vitiligo may be triggered by particular events, such as:
- stressful events, like childbirth
- skin damage, such as severe sunburn or cuts (this is known as the Koebner response)
- exposure to certain chemicals – for example, at work
Vitiligo isn't caused by an infection and you can't catch it from someone else who has it.