The underlying mechanism which causes Vitiligo is loss of melanin. This occurs due to destruction of existing melanocytes and defective formation of new melanocytes. However, the precise reason for white spot on skin that is loss of melanin and what causes the destruction of these pigment-forming cells is not completely understood.
A combination of auto-immune, genetic and environmental factors has been seen as Vitiligo causes, in most cases. Recent studies have demonstrated that Vitiligo may also be caused by stress which affects the immune system, leading the body to react and mistakenly destroy the melanocytes by releasing antibodies against them.
Heredity has been strongly proposed as one of the Vitiligo cause, since many cases with Vitiligo do report incidence of this condition (or other auto-immune disorders) in their family. Research has also shown the NALP1 gene to be the trigger in predisposing people to Vitiligo.
Additionally, Vitiligo is said to be associated with (and affecting people with) certain auto-immune and inflammatory diseases such as:
- Hypothyroidism - Under -functioning of thyroid gland
- Hyperthyroidism - Over -functioning of thyroid gland
- Diabetes mellitus
- Addison's disease
- Alopecia areata
- Pernicious anemia
Possible things that can trigger Vitiligo in an individual who is genetically prone include:
- Skin trauma
- Sun burn
- Emotional stress
- Skin rash
- Exposure to de-pigmenting chemicals - the disease can later spread beyond areas of contact via immune-mediated mechanism. Phenolic/catecholic derivatives are the prime chemicals causing this.
All said and done, the exact reason why Vitiligo affects some people and not others, and that too with such unpredictability, still remains unexplored!