The transverse anatomy of androgenic alopecia.

Twenty-five biopsy specimens from the balding frontal scalp of five patients were studied. Processing included vertical and transverse (horizontal) sectioning, toluidine blue and hematoxylin and eosin staining, and fixed and frozen sectioning. Findings included decreased hair density, increased numbers of vellus hairs, and alteration of the normal follicular architecture. Transverse frozen sectioning with toluidine blue staining appeared to be a rapid and reliable tool for studying androgenic alopecia.