15th April 2024

Hirsutism and hypertrichosis

Hirsutism

Hirsutism is an excess of terminal hair growth in the androgen-sensitive areas such as the upper lip, chin, abdomen, back and buttocks. Androgens increase hair follicle size and promote coarse, dark hair growth. PCOS is the most common cause of hirsutism. The following table outlines the androgenic and non-androgenic causes of hirsutism.

Table 1 outlines the androgenic and non-androgenic causes of hirsutism

Virilism

Virilism is a severe condition which has the features of hirsutism with the added masculine secondary sexual characteristics. This includes a deepened voice, clitoromegaly and the development of a male habitus. If these features are present, CAH, ovarian hyperthecosis and androgen-secreting tumours should be investigated.

Hypertrichosis

This is a condition that differs from hirsutism in that it is due to excess hair growth in androgen-independent areas occurring anywhere on the body. Acquired hypertrichosis can be caused by anorexia secondary to hormone imbalances or iatrogenic through medications such as ciclosporin, minoxidil and acetazolamide.

References

• Robert L Barbieri et al., Pathophysiology and causes of hirsutism (2021) <https://www.uptodate.com/contents/pathophysiology-and-causes-of-hirsutism>