Case study: fibrosing alopecia in a pattern distribution localized on alopecia androgenetica areas and unaffected scalp.

A 54-year-old man with a 24-year history of androgenetic alopecia was referred to the Department of Dermatological Sciences with follicular inflammatory lesions leading to scleroatrophy in the vertex region (Figure 1) of 1-year duration. These lesions appeared a year ago. There was no previous history of this condition. On examination, the patient showed confluent infiltrative follicular lesions on the frontoparietal and occipital scalp (Figure 2). Some lesions evolved into erosions that developed in ivory white scleroatrophy within weeks. These lesions were localized both in and outside of are as affected by alopecia androgenetica and were associated with mild pruritus. Histopathologic examination, performed on an early lesion of the vertex, documented a mild thinning of follicular epithelium associated with an intense lymphohistiocytic perifollicular infiltrate. The damage of the basal cell layer was limited to the follicle, while epidermis was intact. In particular, follicular keratinocytes under the isthmus showed a very intense degeneration exactly where the infiltrate was the most prominent. The damage of the hair sheath was under the isthmus and involved the lower portions of the follicles (including the hair bulbs). The inflammatory infiltrate was exclusively represented by perifollicular lymphohistiocytes. Finally, a connective fibrotic shell with numerous fibroblasts formed a sheath around the atrophic follicle (Figure 3). Results of laboratory investigations (including complete blood cell counts, basal thyroid-stimulating hormone, C-reactive protein, serum ferritin levels, B and C hepatitis markers, antinuclear antibodies, and cultural examinations) were negative.We diagnosed the patient with fibrosing alopecia in a pattern distribution.