Melanin
Vitiligo is relatively commonly acquired loss of pigmentation of the skin, affecting 1% to 2% of the population. It is said to be due to the destruction of Melanocytes, or melanin (pigment cells), which results in white patches. The most common sites of pigment loss are body folds (like the groin or armpits), around body openings, and sun exposed areas like the face or hands and neck. It can also develop at sites of injury: cuts, scrapes, and burns.Our skin contains a substance called melanin which is a dark pigment, and it is what gives our skin its color. Melanin is a Greek word which means black. It is a pigment that is being found in most organisms derived from the amino acid tyrosine. Melanin is the primary determinant of skin color and protects the skin from the harmful rays of the sun. It is also found in hair and the pigmented tissues underlying the iris of the eye.
The melanin in the skin is produced by Melanocytes, which are found in the basal layer of the epidermis. Although human beings generally possess a similar concentration of Melanocytes in their skin but the Melanocytes in some individuals and ethnic groups expresses more frequently or less frequently the melanin-producing genes than others, thereby conferring a greater or lesser concentration of skin melanin.
Sometimes, parts of the skin also stop producing melanin or the melanin already present in the body is destroyed without any significant cause and the area become deficient of melanin. This deficient area in melanin appears as white patch of Vitiligo. This is the beginning of Vitiligo disease.
Vitiligo may start as a small white patch/spot and spread rapidly to all the parts of the body or it may gradually spread with years. No one can be sure of its speed as well as the causes of Vitiligo is still a mystery to be solved. If in case any part of the scalp is affected, the hair growing from the area will also be devoid of coloration. In very few cases the retina is also affected due to Vitiligo.
