Vitiligo is a loss of skin melanocytes that causes areas of skin depigmentation of varying sizes. The cause of the disease is unknown, but the condition may be autoimmune, as up to one third of patients have evidence of other autoimmune disease.
Diagnosis is often obvious on examination. Vitiligo is characterised by depigmented areas, usually sharply demarcated and often symmetric. Hair in vitiliginous areas is usually white.
Some patients have autoantibodies to melanin. Up to 30% show other autoantibodies, for example thyroglobulin antibodies, antibodies against adrenal cells, and gastric parietal cell antibodies, or clinical autoimmune endocrinopathies such as Addison’s disease, pernicious anaemia, diabetes, and thyroid dysfunction, leading to speculation that vitiligo is an autoimmune disease. However, the relationship is unclear and may be coincidental. The strongest association is with hyperthyroidism (eg., Graves’ disease) and hypothyroidism (eg., Hashimoto’s thyroiditis.