Reply to Comment on: Pattern Hair Loss. Assessment of Inflammation and Fibrosis on Histologic Sections

In response to comments on their work regarding pattern hair loss, the authors, Manuel Valdebran, Linda Doan, and Dirk M. Elston, discuss the importance of uniform characteristics in alopecia studies and address specific findings from other studies. They note that IgM deposition in the epidermal basement membrane zone (BMZ) is a non-specific finding, while follicular BMZ deposition suggests lupus erythematosus, which responds differently from pattern alopecia. The authors emphasize the need for matched controls in studies, considering factors like body site and sun exposure that affect immune deposits. They reference a study by Young et al., which found granular deposits of IgM or C3 in hair loss patients and controls, and the presence of porphyrins in hair loss subjects, which could be excited by ultraviolet radiation from Propionibacterium acnes. Another study by Siu-Yin Ho et al. found elevated P. acnes in miniaturized vertex hair of hair loss patients compared to controls. The authors agree on the necessity of further studies with matched controls and suggest that a prospective study with comprehensive analyses would be ideal. The document is partially funded by the Mentorship Grant of the American Hair Research Society.