Resistance of Transplanted Hair Follicles to the Onslaught of Diffuse Alopecia Areata

Abstract

A 55-year-old man who previously underwent a successful hair transplantation for androgenetic alopecia now presents with rapid onset hair loss over the anterior to mid-scalp areas during a 2-month period. The alopecic area noticeably extended diffusely from anterior hairline to scalp vertex while rows of previously transplanted hair follicles appeared intact. Further dermoscopic features and a scalp biopsy were consistent with alopecia areata incognita. This patient was subsequently successfully treated with intralesional steroid injections. This case report is the first demonstrating the relative resistance of transplanted hair follicles to the process of alopecia areata when compared with local indigenous hairs. Prior to this, a few reports have demonstrated the use of hair transplantation to treat stable areas of alopecia areata resistant to medical treatment with mixed results but at least some initial success. This could be related to the local irritation and inflammatory response resultant from needling during hair transplantation that causes a degree of scarring and fibrosis around each transplanted graft, hence lending a protective barrier to an autoimmune-based T-lymphocyte attack on hair bulbs and subsequent increased survival of transplanted hair follicles. This unexpected observation provides new avenues for investigation into alopecia areata pathophysiology and further supports hair transplantation as a viable option for patients with stable, localized alopecia areata that is recalcitrant to other modalities.