Androgenetic alopecia

Androgenic alopecia (AGA) is a non scarring, progressive miniaturization of the hair follicle which has a characteristic pattern of distribution (1,2).

• this is a common disorder affecting genetically predisposed men and women
• the prevalence increases with age in both sexes
• genetic factors determine age of onset and severity.

Hair loss is usually insidious, presenting as thinning rather than shedding.

In men

• tend to lose hair over the crown, along the frontal hair line, and the temples
• occasionally a female pattern of hair loss can be seen as well
• type 2 5 alpha-reductase is to believed to be important in the development of male-pattern baldness.

In women

• hair loss over the frontal and central areas, but the parietal and occipital regions may be involved as well
• occasionally it may occur in a male pattern as well

Reference:

1. Lolli F, Pallotti F, Rossi A, Fortuna MC, Caro G, Lenzi A, Sansone A, Lombardo F. Androgenetic alopecia: a review. Endocrine. 2017 Jul;57(1):9-17.
2. European Dermatology Forum. S3 - European Dermatology Forum guideline for the treatment of androgenetic alopecia in women and in men. 2017 [internet publication].