Albinism and vitiligo
Disturbances of metabolism of pigments are different. Some cause only cosmetic problems and others lead to serious illnesses. General in albinos and people suffering from vitiligo is that they observe abnormal melanin synthesis. The color of skin, hair and eye is due to pigment, called melanin. It is produced and accumulated in the form of granules of brownish to black colour in cells called melanocytes. These cells come from the nervous system, migrate during embryonic development and are spread in the entire surface of the body. Different color with representatives of different races is due to uneven melanin content in the skin. Melanin is contained elsewhere in the body. This pigment is present in the hair and body hairs, mucous membranes, meninges, substantia nigra in the brain, the iris of the eye. Iris diagnosis is a valuable diagnostic method, which seeks a link between pigmentation in the iris of the eye and diseases.
The formation of melanin is controlled by the pituitary gland that secretes melanocyte stimulating hormone in stimulation with ultraviolet light. The result of this stimulation is accumulation of melanin in the skin. The complete absence of melanin in the body is a congenital condition called albinism. Albinos are people with white hair and red eyes. Their skin is very sensitive to sunlight, because of lack of the protective effect of melanin. Event short termed sun exposure in albinos leads to severe skin irritation and burns. Loss of melanin in certain areas of the skin is acquired disease, most often as a result of previous skin disease, and is called vitiligo. Various reasons can cause vitiligo, even in most patients the specific reason for the disease remains unclear.
Ultraviolet rays have effects which may lead to skin cancer. It is proved that cancer of the skin is common in warm countries in people working outdoors. This cancer is very rare in those who protect their face with a hat. Also skin cancer occurs mainly in fair – skinned races. For negroid race, it is rare because the large amount of melanin protects them from ultraviolet rays. Melanin has a protective function. Gaining this pigment, the body builds a barrier to UV rays and prevents their penetration into deeper tissues. Tan or tan skin that develops in sun exposure is due to the greater amount of melanin in melanocytes. Tan evidence that we have suffered a great deal of ultraviolet radiation.
Since UV rays are so dangerous, then quite reasonable arises the question: “why in the summer every year en masse all rush to the sea, bake like lizards in the sun and run the risk to catch skin cancer? Is there a benefit of tan, except that we become more beautiful?” In the skin under the influence of sunlight is accumulated vitamin D. It is well known that this vitamin is responsible for the proper functioning of calcium and phosphate metabolism. Vitamin D is vital since early childhood. It protects the growing body of rachitis and in adults is an important factor in prevention of osteoporosis. Less well – known effect of vitamin D is its stimulate effect over immunity. This is also due to “tempered” result of sea procedures. Excessive exposure to ultraviolet radiation is dangerous! Furthermore, skin burns can result in activation of melanocytes in a nevus and from moles come one of the most malignant tumors in human pathology – malignant melanoma.