Androgenetic Alopecia: Modeling Progression and Regrowth
April 2016
in “
Experimental Dermatology
”
androgenetic alopecia male pattern hair loss female pattern hair loss hair follicle miniaturization hair cycle terminal hairs secondary vellus hairs scalp biopsies unit area trichograms phototrichograms anagen duration telogen duration kenogen follicles AGA male pattern baldness female pattern baldness hair thinning hair growth cycle thick hairs fine hairs hair biopsy hair density measurement hair growth phase hair shedding phase
TLDR AGA causes hair loss through follicle miniaturization and hair cycle changes; regrowth depends on anagen initiation in kenogen follicles.
This scientific paper discusses the pathogenesis of androgenetic alopecia (AGA), which produces male pattern hair loss and female pattern hair loss. The paper explains that hair follicle miniaturization and changes to the hair cycle are involved in AGA. Hair follicle miniaturization involves the conversion of terminal hairs into secondary vellus hairs, which is recognized in scalp biopsies, unit area trichograms, and phototrichograms as a reduction in the number of terminal hairs per cm² and an increase in the number of vellus hairs per cm². The changes in hair cycle dynamics include shortening of anagen duration and an increase in telogen duration. The paper also discusses the conflicting results of studies on hair regrowth and the importance of initiation of anagen in kenogen follicles for successful treatment of AGA.
