Aetiology
Based on the aetiology, hirsutism can be divided into 3 categories: idiopathic, hyperandrogenic, and non-androgenic.[2]
Idiopathic hirsutism
These women have no identifiable aetiology for the excessive hair growth. They have normal androgen levels and regular menstrual cycles. Idiopathic hirsutism accounts for 5% to 15% of all cases. Possible causes include increased androgenic sensitivity in the pilosebaceous unit, increase in conversion of testosterone to dihydrotestosterone, or androgen receptors changing their function.[2]
Hyperandrogenic hirsutism
Hyperandrogenic hirsutism (HH) is the most common category, responsible for over 80% of cases and is usually caused by an overproduction of androgen from the ovaries or adrenal glands. Patients with HH typically have irregular menses, anovulation, infertility, hyperinsulinaemia, and have a greater risk of developing endometrial hyperplasia or neoplasia due to the unopposed oestrogen.[2] Causes of HH include:
Polycystic ovary syndrome (PCOS): accounts for 72% to 82% of all hirsutism cases
Non-classic congenital adrenal hyperplasia
Androgen-secreting ovarian tumours
Sertoli-Leydig cell tumours (androblastoma, arrhenoblastoma)
Granulosa-theca cell tumours
Hilus-cell tumours
Ovarian hyperthecosis (a condition with features similar to PCOS, but with more severe androgenisation). May occur post-menopausally; the cause is luteinised theca cells, which become hormonally active.
Non-androgenic hirsutism
Women may develop hirsutism due to certain drugs, such as:[2]
Danazol
Performance-enhancing anabolic steroids
Ciclosporin
Diazoxide
Penicillamine
Interferon
Phenytoin
Cetuximab
Corticosteroids
Androgen creams or patches
Progestins
Oestrogen antagonists (e.g., tamoxifen).
Endocrinopathies, such as hypo- or hyperthyroidism, hyperprolactinaemia, or Cushing's syndrome may also cause hirsutism, though this is uncommon and usually associated with other signs and symptoms of these conditions.
Use of this content is subject to our disclaimer