Skin pigmentation in teens
The pigmentation in these stripes seems to be a result of the hormone changes that take place in adolescence. They are not due to stretching of the skin from rapid weight gain. Nor do they have any direct relationship to the striae that appear on a woman's body during pregnancy. The pigmented striae of adolescence may last months, but eventually they fade out and disappear, leaving no scars.

Decreased Pigmentation Of The Skin
The only real "white man" is a true albino, no matter from what racial stock he comes. The albino does not have the pigment in the skin that gives the flesh color of others in his ethnic group. His hair has no pigment either, and thus is quite white. There is an absence of protective pigment on the inner lining of the albino's eye (the choroid), so an accompaniment of albinism is an acute sensitivity to light (photophobia). Nystagmus, a flickering movement of the pupils, is also seen with albinism.
 
Albinism is a hereditary condition. In many cases a child with the signs of albinism will, as he grows older, take on some pigmentation and his skin, hair, and eyes will become more normal. Occasionally the albinism stays marked throughout adult life.

Some people have a white or partially white eyebrow, or a streak of white hair, or other small patches of partial albinism. This strikingly distinctive addition to a person's appearance has been copied by artificial means—showing again that imitation is the sincerest form of flattery. Albinos have a charm of their own.

Many people have patches of skin lacking the usual pigment. These patches can be small or large and of varying shapes. They are given the medical term vitiligo. Each patch has a definite though irregular border. Vitiligo is usually not permanent, though its spots may retain the same size and shape for years. It usually shows up much more definitely when the skin is sunburned or suntanned, because there is no deepening of color in its area while the surrounding skin becomes darker.

The cause of this harmless condition is not known. Various folk traditions hold that this patchy absence of pigmentation is contagious, or signals a visitation of an evil spirit. This, obviously, is nonsense. There is never itching or pain with vitiligo, and the condition never becomes malignant.

A new form of treatment is now available for these patches, a medication derived from ancient Egyptian folk medicine. However, to date, the pigment-stimulating ingredients of the plant Ammi majus Linn, which the Egyptians tried for vitiligo, have been found to work properly in only one out of seven patients. When the plant's ingredients were rubbed on the skin, blistering and pain made the treatment unbearable for many patients. The usual way of taking the drug now is by mouth, but nausea, nervousness, headaches, or other bad reactions may occur. It is therefore necessary that a physician's directions always be followed when this medicine is used.