Quantitative image analysis of hair follicles in alopecia areata.

We took biopsies from similar sites on the scalps of normal controls, normal looking and hair loss areas of patients with alopecia areata. The specimens were sectioned serially and horizontally. We measured morphological parameters, such as the diameter of the hair shaft, the thickness of the inner root sheath, the diameter of the outer root sheath, the irregularity of the outer root sheath and the ratio between the diameters of the hair shaft and the outer root sheath, using a computerized image analysis system. There were significant differences in 5 parameters between hair loss areas and normal controls. The proportions of vellus and telogen hair were significantly higher in the areata areas than in the controls. The 5 morphological parameters and most quantitative-measured parameters of normal-looking areas from patients with alopecia values intermediate between the other groups.