The role of inflammation and immunity in the pathogenesis of androgenetic alopecia.

BACKGROUND: Female pattern hair loss affects many women; its pathogenetic basis has been held to be similar to men with common baldness.

OBJECTIVE: The objective of this study was to determine the role of immunity and inflammation in androgenetic alopecia in women and modulate therapy according to inflammatory and immunoreactant profiles.

MATERIALS AND METHODS: 52 women with androgenetic alopecia (AA) underwent scalp biopsies for routine light microscopic assessment and direct immunofluroescent studies. In 18 patients, serologic assessment for antibodies to androgen receptor, estrogen receptor and cytokeratin 15 was conducted.

RESULTS: A lymphocytic folliculitis targeting the bulge epithelium was observed in many cases. Thirty-three of 52 female patients had significant deposits of IgM within the epidermal basement membrane zone typically accompanied by components of complement activation. The severity of changes light microscopically were more apparent in the positive immunoreactant group. Biopsies from men with androgenetic alopecia showed a similar pattern of inflammation and immunoreactant deposition. Serologic assessment for antibodies to androgen receptor, estrogen receptor or cytokeratin 15 were negative. Combined modality therapy with minocycline and topical steroids along with red light produced consistent good results in the positive immunoreactant group compared to the negative immunoreactant group.

CONCLUSION: A lymphocytic microfolliculitis targeting the bulge epithelium along with deposits of epithelial basement membrane zone immunoreactants are frequent findings in androgenetic alopecia and could point toward an immunologically driven trigger. Cases showing a positive immunoreactant profile respond well to combined modality therapy compared to those with a negative result.