What is a scalp biopsy? Which hairs should be taken ?
A scalp biopsy is a 15-20 minute procedure that helps the dermatologist obtain a small piece of tissue for analysis. The sample is processed in a history laboratory into thin sections and mounted on glass slides for review by a pathologist under the microscope. A scalp biopsy is not required for most patients with hair loss. When the diagnosis is uncertain, it can be very helpful.
Which hairs should be included?
First, an area of the scalp containing hair follicles should always be included in a biopsy. A scalp biopsy specimen from a completely bald area is not helpful!
Second, the hair follicles obtained should be taken from an area showing the specific abnormalities thought to be in keeping with the hair loss condition in question. If no such features are present, hair follicles might be obtained from an area of the scalp where the hairs are easily extractable (positive pull test), or from an area having the most symptoms (itching, burning or pain).
The key point is that obtained a scalp biopsy from a random area on the scalp does not usually yield useful information.
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Vancouver office at 604.283.9299