Androgenetic alopecia

Androgenetic alopecia, also known as pattern hair loss, is a genetically determined, patterned, progressive loss of hair from the scalp.

Men present with hair thinning in the temporal areas (producing a characteristic M shape) that advances to the crown (vertex) area as the alopecia progresses. Women usually have more diffuse thinning on the crown area, and less commonly present with a male-type pattern.

Diagnosis is clinical and is based on recognising the pattern of hair loss.

Possible treatments are oral finasteride and/or topical minoxidil solution or foam for men, and topical minoxidil solution or foam for women.

For women with female-pattern hair loss and concomitant hyperandrogenism (<40% of cases), additional androgen-suppressive therapy may be considered.

A genetically determined, patterned, progressive loss of hair from the scalp. The term androgenetic alopecia is best used only when referring to male-pattern hair loss, as most females likely do not share the androgenic pathway. A more appropriate term for women is female-pattern hair loss. The term ‘pattern hair loss’ will be used in this topic when referring to hair loss affecting both sexes.

In men, hair loss is caused by androgen-mediated follicular miniaturisation that leads to fine, short, non-pigmented, vellus hair formation. The pathogenesis of female-pattern hair loss has not been well characterised, and androgens are not believed to play a major role for most women.