DNA Explainer: What is Vitiligo? Know the truth about the highly stigmatized skin condition

Vitiligo is a chronic skin autoimmune condition which results in the formation of white or light patches on our body.

Also known as Leukoderma, the disorder is prevalent across India, amounting to between 0.25 and 4 of all outpatient dermatology cases in India, as noted across studies. The highest incidences are found in in Gujarat and Rajasthan with up to 8.8 percent of the skin-problem related outpatients.

There is tremendous stigma attached to vitiligo in India. People with the autoimmune condition suffer from low-self esteem and psychological pressure. Deeply-rooted superstitions attached to vitiligo (belief that the disorder is the product of past sins), combined with lack of awareness becomes a source of lifelong struggle for patients. The stigma hits young women the hardest due to matrimonial problems accompanying it.

The exact cause of this condition and what triggers the immune system to mistakenly attack its own healthy skin pigment cells is still unknown. The discoloration happens when melanocytes or the cells which provides colour to the skin, hair and eyes stop functioning.

According to experts, a combination of factors which includes genetics, autoimmunity, stress, skin damage and chemical exposure likely contribute to an individual’s risk of vitiligo.

Common causes of vitiligo or leukoderma

People of multiple skin types or ethnicities can be affected by vitiligo. While the exact cause has not been discovered yet, the research suggests that multiple factors are at play:

Genetic mutations: Variations in multiple genes are linked to an increased risk of developing vitiligo. Around 30 percent of cases are genetic and about one-fifth of the people with vitiligo have at least one close relative with the same condition. While family history can increase a person’s chances, researchers agree that it is not the sole reason for occurrence of vitiligo.

Autoimmune conditions: Studies show a clear genetic link between Vitiligo and other autoimmune diseases, which includes those that specifically affect the thyroid gland. While the exact cause is still being studied, it can happen because the immune system of patients suffering from vitiligo develop antibodies that destroys the skin pigmentation cells.

Around 15 to 25 percent of people with Vitiligo have at least one other autoimmune disease. People who have an existing autoimmune disease, such as rheumatoid arthritis or hypothyroidism are at an increased risk of developing vitiligo.

Environmental triggers: External factors such as stress, skin trauma or exposure to strong chemicals seems to trigger Vitiligo development in people who are genetically predisposed to the condition.

Triggers might also cause Vitiligo patches to spread or develop in people who already have the condition. For example- The first symptoms of skin pigmentation loss may show up on an area of skin which has come in contact with chemicals or skin damage. The condition might worsen after a person experiences intense emotional and physical stress.

Genetics: Researchers have found variations in more than 30 genes which are linked to an increased risk of developing vitiligo. Most genes are involved in body’s immune system or melanocyte function.

Although some researchers are aware that some individuals are at a higher risk of developing Vitiligo due to having certain genetic mutations, the reasons why these changes occur are not completely clear and emphasize why there are other contributing factors at play.

Lifestyle Risk Factors

There is no way to know exactly whether a person will be infected by vitiligo or not.  However, experts have identified many risk factors that can increase the chances, particularly if the person has a genetic predisposition to the condition.

Skin Damage or Trauma: According to studies, stressful events or chronic emotional or physical stress may trigger the development of vitiligo, especially patients who are predisposed due to their genes. Triggering of skin changes is likely, especially in the part due to the hormonal changes which occur when a person undergoes extreme stress. Evidence has also shown that trauma and huge life stressor are linked to the autoimmune disease.

Chemical exposure: Exposure or contact to certain chemicals may be another external risk factor for developing the disease. Some experts have said hypothetically that the chemicals help in the progression of stress pathways which are already present in the melanocytes leading to autoimmune inflammation. Additionally, genetic influence can increase cellular stress in melanocytes or set a lower threshold for stress which can be handled by the immune system.

A chemical named monobenzone can trigger skin depigmentation to develop and worsen in people who already have Vitiligo. Phenols are another category of chemicals that may play a role in Vitiligo which is thought to disrupt Melanocyte function. These chemicals are found in products as ingredients like adhesives, disinfectants, paints, insecticides and more.