Your skin gets its colour from a pigment called melanin, which is produced by skin cells called melanocytes.
If you have vitiligo, you do not have enough working melanocytes, so not enough melanin is produced in your skin. This causes white patches to develop on your skin or hair.
The causes of non-segmental and segmental vitiligo may be slightly different (see Vitiligo - symptoms more information about the two types).
Autoimmune conditions
Non-segmental vitiligo, the most common type of vitiligo, is thought to be an autoimmune condition. This means that your immune system (the body’s natural defence system) does not work properly.
Instead of attacking foreign cells, such as bacteria, your immune system produces antibodies (infection-fighting proteins) that attack your body’s own healthy cells and tissue.
If you have non-segmental vitiligo, your immune system produces antibodies that destroy the melanocyte skin cells that make melanin.
Vitiligo can be associated with other autoimmune conditions, such as hyperthyroidism (an overactive thyroid gland). See Vitiligo - complications for more information about this.
Neurochemicals
Segmental vitiligo, the less common type of vitiligo, is thought to be caused by chemicals released from the nerve endings in your skin ('neuro' means to do with nerves). These chemicals are poisonous to the melanocyte skin cells.
Risk factors
You may be at higher risk of developing non-segmental vitiligo if:
- you have a family history of the condition; for example, one of your parents has it
- you have a family history of other autoimmune conditions – for example, one of your parents has pernicious anaemia (an autoimmune condition that affects your stomach)
- you have another autoimmune condition
- you have melanoma (a type of skin cancer) or cutaneous T-cell lymphoma (a type of cancer of the lymphatic system)
- you have particular changes in your genes (units of genetic material) that are known to be linked to non-segmental vitiligo
Triggers
It is possible that the vitiligo may be triggered by particular events, for example:
- stressful events, such as childbirth
- damage to your skin, such as severe sunburn or cuts (this is known as the Koebner response)
- exposure to certain chemicals – for example, in your job
Vitiligo is not caused by an infection and you cannot catch it from someone else who has the condition.
