We have some idea of what is happening in vitiligo but are less clear about why it is happening.  We know that pigment cells are not functioning in the white patches although some of them do survive both in the skin and also in the hair follicles in the white patches.  Many theories exist to explain the loss of pigment, the most popular is the autoimmune theory which means that the body’s own immune system is attacking the pigment cells.

It has also been recently established that genes play an important role in predisposing some people to vitiligo, especially those who have other autoimmune diseases, in particular thyroid disease, or who have family members who suffer from vitiligo or these diseases.  This discovery strengthens the autoimmune theory.

Other theories which have been proposed include the neuronal theory which suggests that the nerves in the skin are implicated in the damage to pigment cells and the oxidative stress theory based on the break down of anti-oxidant defences in the skin or in the pigment cell itself.  In addition, high levels of hydrogen peroxide which is toxic to pigment cells have been found in the skin of people with vitiligo.

It is also recognized that environmental factors such as psychological stress, hormonal changes including puberty and childbirth, trauma to the skin, and even exposure to certain chemicals may trigger the disease and could play an important role in its development and progression.