Senescent
alopecia was originally thought to affect people aged 50 years or older with no family history or evidence of pattern balding. It was described as a diffuse thinning involving the whole scalp due to a steady decrease in thick terminal hairs, but without evidence of increased miniaturization. Senescent
alopecia is not a primary diagnosis in this clinic. Most possible examples of it are assumed to be androgenetic or
diffuse alopecia. In the study reported here, horizontal sections of 2149 scalp specimens from individuals with male and female pattern and
diffuse alopecia, as well as from normal controls, were examined, and their follicular counts were recorded and sorted into decades. The decade of 20 to 29 years contained a significant number of patients and was used for baseline follicular counts for comparison with all succeeding decades up to age 99 years. A reduction of 15% below baseline was considered significant. In 10.6% of patients with
male pattern alopecia, the age of onset of a significant reduction in follicular counts was 50 years; in 5.7% of patients with female pattern
alopecia it was 70 years, and in 2.0% of patients with
diffuse alopecia it was 80 years. These data suggest that most cases of significant
hair loss in the elderly are
androgen driven. The few patients with deteriorating
diffuse alopecia may be the exception. The study concluded that old age is not a significant cause of
hair loss.