Dermatopathology of Common Hair Problems

In the 1999 article, David A. Whiting highlighted the importance of using both horizontal and vertical sections of scalp biopsies to improve the diagnosis of hair loss conditions. The article detailed the biopsy technique and the significance of understanding the hair follicle's anatomy and growth cycle for interpreting results. It differentiated between nonscarring alopecia (e.g., androgenetic alopecia, alopecia areata, trichotillomania) and scarring alopecia (e.g., discoid lupus erythematosus, lichen planopilaris), with specific histopathologic features for each. Androgenetic alopecia was notably characterized by a decrease in terminal hairs and an increase in miniaturized hairs. Other conditions like diffuse alopecia, traction and pressure alopecia, and various forms of scarring alopecia such as pseudopelade and folliculitis decalvans were described, each with unique clinical and histopathologic characteristics. The document emphasized the role of scalp biopsy in the differential diagnosis of these hair disorders but did not provide study participant numbers to assess the strength of the findings.