Is vitiligo contagious?

Vitiligo is an autoimmune disease in which the immune system mistakenly attacks melanocytes, the cells located at the dermo-epidermal junction responsible for the production of melanin, a pigment that protects the skin from UV rays. When the immune system is functioning properly, melanin is transferred to keratinocytes, which are involved in the inflammatory response. Two main mechanisms explain this loss in vitiligo: the destruction of melanocytes by CD8+ T lymphocytes and their apoptosis, as well as a defect in melanocyte adhesion, leading to their detachment from the basal lamina.

Vitiligo is not a contagious disease.

It does not result from a viral, bacterial, or fungal infection, nor from a transmissible pathogen like contagious diseases, and cannot be transmitted through physical contact, air, or blood. Dermatological and immunological studies confirm that vitiligo is strictly non-transmissible, as it is based on an internal malfunction of the immune system and not on an external agent.

However, genetic predispositions do exist for vitiligo and can cause confusion. Indeed, according to various sources, 20% of people affected by vitiligo have at least one first-degree relative with this disease, and these individuals are 7 to 10 times more likely to develop vitiligo. Over 50 susceptibility genes, including HLA, CTLA4, NLRP1, and TYR, have been associated with the disease. Individuals carrying variants of these genes have an increased risk of developing vitiligo, but they are not systematically affected. However, heredity alone is not sufficient as environmental factors can also play a role, including stress, the Koebner phenomenon, or even chemicals.

1. "Vitiligo is transmitted through physical contact."

   False, contrary to infectious diseases, vitiligo is not caused by a virus, bacteria, or fungus. Therefore, it cannot be transmitted by touching a person who has it.

2. "Vitiligo can spread through the bloodstream."

   False, vitiligo is an autoimmune disease where the immune system mistakenly attacks the melanocytes. There is no pathogen in the blood of affected individuals, therefore there is no risk of transmission through blood transfusion or exchange of bodily fluids.

3. "Vitiligo is a hereditary disease, hence it can be passed on."

   Partially true, there is a genetic predisposition, but this does not mean that a person's child will necessarily develop the disease. Approximately 20 to 30% of cases have a family history, but other environmental factors (stress, UV rays, dust mites) play a triggering role.

• SCHALLREUTER K. U and KRÜGER C. Stigmatisation, Avoidance Behaviour and Difficulties in Coping are Common Among Adult Patients with Vitiligo. Acta Dermato-Venereologica (2015).

• Pathophysiology and mechanisms underlying vitiligo. Vitiligo Bordeaux-Clinical Research Department.

• BOUKHEDOUNI N. Immunological mechanisms involved in the loss of melanocytes during vitiligo. Human Medicine and Pathology. University of Bordeaux (2018).

• EZZEDINE K. & al. Vitiligo: A Review. Dermatology (2020).