The study of hair follicle counts from scalp histopathology in the Thai population.
Level 4 - case-series / case-control
Cross-sectional descriptive histopathological study
PubMed 32501534 · doi:10.1111/ijd.14989
What was done
Researchers obtained 4-mm punch biopsy specimens from the occipital scalp of 90 Thai subjects with clinically normal hair and scalp. Specimens were horizontally sectioned to quantify follicular units, total hair follicles, hair types (terminal vs. vellus), and hair cycle phases (anagen vs. telogen). Outcomes were evaluated across sexes, age groups, and compared against historical data from other ethnic populations.
What was found
Among 90 specimens, the mean counts per 4-mm punch were 20.5 ± 5.2 total hairs, 18.2 ± 4.1 terminal hairs, a median of 2 (range 0–7) vellus hairs, and 9.1 ± 1.6 follicular units. The mean terminal-to-vellus hair ratio was 8.9:1, and the anagen-to-telogen ratio was 91.9:7.9. No significant differences were observed between sexes, and counts did not correlate with age. Hair density in Thais was lower than reported values for Caucasians and Hispanics, comparable to Africans, and intermediate between Koreans and Iranians.
Why it matters
This study provides normative histopathological reference values for horizontal scalp biopsies in the Thai population, aiding pathologists and dermatologists in accurately diagnosing scarring and non-scarring alopecias in Asian patients.
Limits
Biopsies were limited solely to the occipital scalp, meaning values may not represent frontal, temporal, or vertex scalp regions. The abstract does not report the age distribution or inclusion/exclusion criteria for subject selection.
Cited by
- supports The human scalp contains approximately 70,000 to 100,000 hair follicles on average.