Here are five things you may not know about poliosis:
1. What it is: Actor Johnny Depp sports one in the movie Sweeney Todd. Blues singer Bonnie Raitt proudly displays hers. We're talking about a white forelock or streak. The medical name for this natural tuft of white hair is poliosis, from the Greek word — "pilios" — for gray.
2. Where it happens: While the white patch occurs most often along the forehead, poliosis can involve eyebrows, eyelashes or hair anywhere on the body.
3. Why it happens: This is not a disease. Most people with poliosis are healthy and experience it only because there is no pigment in the hair and skin in that area. It can be hereditary.
4. When little Johnny goes gray: Gray hair in a child is uncommon and should be evaluated by a doctor. It could just be a matter of premature graying, but some early loss of hair color can be associated with thyroid disorders, vitamin B-12 deficiency and other conditions.
5. An overnight phenomenon?: While some people claim psychological shock or trauma can turn hair gray overnight, many scientists doubt it happens that quickly. Prevailing medical opinion traces rapid hair whitening to a genetic autoimmune disease called alopecia areata in which T cells mistake hair follicles for a foreign substance and aggressively attack them, sometimes targeting only pigmented hairs.
No comments:
Post a Comment