More is Not Always Better in Hair Growth Factors. Epidermal Growth Factor: Hair Growth Factor Involved in Alopecia Areata Pathogenesis.

Background: Alopecia areata (AA) is the second most frequent nonscarring alopecia after androgenetic alopecia; the trigger factor induces changes in the growth plate of hair bulb and leads to premature termination of anagen phase. Epidermal growth factor (EGF) can be the key molecule that participates in initiation and suppression of normal hair growth cycle. The role of EGF in the pathogenesis of AA is still uncertain.