S5 INVASIVE METHODS: FOLLICULAR COUNTS IN SCALP BIOPSIES
Whiting DA
Baylor Hair Research and Treatment Center, Dallas, Texas, USA

A full thickness 4mm punch biopsy of the scalp, preferably sectioned horizontally, can be valuable in the diagnosis of a non-scarring alopecia. Pattern hair loss, diffuse alopecia such as telogen effluvium, alopecia areata, and trichotillomania can be distinguished from one another; characteristic differences can usually be seen in follicular counts, terminal to vellus ratios, and anagen and telogen percentages. Horizontal sections of serial biopsies at baseline and after treatment can be useful in the evaluation of drugs for hair loss. In a placebo-controlled finasteride study a cohort of 26 men were biopsied at baseline and month 12. Horizontally-sectioned biopsies were read, blinded to patient and time, for counts of terminal and miniaturized hairs and anagen and telogen hairs. After one year of finasteride, terminal hairs increased and vellus-like hairs decreased. These changes were not noted in the placebo patients. At 5 years, the trend continued in the 12 remaining patients. In the 5 year study, the sections were evaluated by image analysis. Individual hair widths were measured and a mean hair diameter for each biopsy was derived. This allowed a standardized comparison of hair growth in biopsies from different sites. During the 5 year period, the patients on finasteride showed a hair width increase of 29.19% over the placebo hairs. Biopsies from all patients in the study of finasteride 1mg in post menopausal females were similarly studied. No differences in follicular counts were demonstrated between finasteride and placebo patients. Biopsies have been taken from patients at 2 sites in a recent trial of a biologic in alopecia areata. 17 patients were biopsied at baseline and after 12 weeks of active drug or placebo. The follicular counts have been read, with the results collated and awaiting decoding. Image analysis is pending and will be utilized for evaluating follicle and cell counts with standard H & E stains and various immunostains. The methods used will be demonstrated.