'A detective look' at hair biopsies from African-American patients.

BACKGROUND: A patient's ethnicity can be an important clue in the diagnosis of scarring alopecia as some disorders such as traction alopecia (TA) and central centrifugal cicatricial alopecia (CCCA) are more prevalent in or exclusive to African-Americans.

OBJECTIVES: To perform a retrospective review of 60 scalp biopsies from African-American patients including 25 cases of CCCA, 22 cases of TA, five cases of frontal fibrosing alopecia, three cases of discoid lupus erythematosus, three cases of hair breakage and two cases of alopecia areata.

METHODS: Serial horizontal and vertical sections were examined.

RESULTS: Features characteristic of the African-American scalp include: golf club-shaped bulb, elliptical shape of the hair shaft, asymmetrical outer root sheath and paired grouping of hair follicles. Clues to the diagnosis of CCCA include: premature desquamation of the inner root sheath, goggles and naked hair shafts in fibrous streamers. Diagnosis of TA is suggested by preserved sebaceous glands along with follicular miniaturization and drop-out.

CONCLUSIONS: The clues reported here aim to help the dermatopathologists to: recognize at a glance that they are dealing with a scalp biopsy from an African-American patient; make the most probable diagnosis by connecting the clues (even if only vertical sections are present); and understand the morphological basis for the susceptibility of the African hair to damage.