Quantitative study of the human hair follicle in normal scalp and androgenetic alopecia.

We carried out a quantitative study of the matrix and dermal papilla of the human hair follicle of the scalp, both normal and in various degrees of androgenetic alopecia. A stereological study showed the measured parameters to decrease with increase in the degree of alopecia, particularly as regards the total volume of the matrix and its papilla. The ratio of the two volumes increased by 30%, indicating a much more marked decrease in size of the papilla than in the matrix size. The number of cell nuclei in the matrix and the papilla of alopecic scalp was found to be 30% and 50% smaller, respectively, than those of normal scalp. Finally, a morphometric study revealed enlarged nuclei in the matrix and papilla, as shown by their increased areas, perimeters, and maximal diameters.