Alopecia

Alopecia is the medical term for hair loss, which may be due to a wide variety of causes. It is not a specific diagnosis but may be due to a wide variety of causes. In general, hair loss can be categorized by 2 criteria: localized vs. diffuse, and scarring vs. non-scarring. In localized hair loss, the thinning occurs in isolated areas or patches, while in diffuse hair loss it is seen as thinning over a larger area of the scalp. In non-scarring hair loss, the follicles remain unharmed though they are not making hairs, while in scarring hair loss, the follicles are lost and cannot regrow hair even after the underlying problem has been treated. Clinically, scarring appears as loss of the follicular openings, creating a smooth, shiny, white, scar-like appearance. Using these criteria can help to quickly narrow the differential diagnosis as well as to prioritize which cases are more urgent – cases of scarring alopecia require more urgent dermatologic assessment as they can result in permanent hair loss.  

Differential diagnosis for alopecia (hair loss):