Tanning

TANNING, brown pigmentation of varying intensity of the skin from the action of direct or reflected ultraviolet rays of sunlight or artificial sources of ultraviolet radiation. The anatomical substrate is the accumulation of melanin grains in the upper pole of the cells of the Malpighian layer above their nuclei, which together with the absence of 'sunburn' on heavily tanned skin is seen as a protective reaction of the body. It develops either gradually, without inflammatory phenomena, or immediately following a 'sunburn'. People with dark skin and high hemoglobin content in the blood tan faster and more intensely than blondes and anemics. Diseases causing anemia lead to rapid disappearance of the tan. People who tan easily and intensely are more resistant to physical labor and infections than those who tan weakly or not at all. For the latter, heliotherapy is contraindicated. To determine the intensity of tanning, pigmentometers have been proposed. When wiping tanned skin with a wet cotton swab, the latter becomes colored brown, which is also observed in Addison's disease and is absent in true pigment spots. To protect against tanning, quinine ointments (on yellow vaseline) and brown fabrics are used.