The culprit appears to be hair styles -- including extensions -- that pull the hair tightly, Kyei said. This causes scarring that leads to permanent hair loss.
The study doesn't point a finger at hair-relaxing products, but Shapiro said the jury's still out on their role in baldness.
So what should black women do?
"If you think that you're having hair loss, you need to have it evaluated to see if it's this type of hair loss," Kyei said. "If you're relaxing your hair, if you're having tight braids, I would just put that on hold until you find out what's going on with your hair."
You may wish to ask for a referral to a dermatologist who specializes in hair, Kyei said. While dermatologists are trained in treatment of skin, hair and nails, some focus specifically on hair. "Hair disorders are one of the hardest areas in dermatology, and it takes a lot of investigation to figure out what's going on," she said.
The study was published online April 11 in the journal Archives of Dermatology.
Learn more about hair loss from the U.S. National Library of Medicine.
SOURCES: Angela Kyei, M.D., M.P.H., chief resident, Institute of Dermatology and Plastic Surgery, Cleveland Clinic, Ohio; Jerry Shapiro, M.D., clinical professor, Department of Dermatology and Skin Science, University of British Columbia, Canada, and adjunct professor, Department of Dermatology, New York University, New York City; April 11, 2011, Archives of Dermatology, online
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