Hirsutism and virilisation: the mFG score, the androgen-excess differential, and the management ladder (Endocrine Society 2018)

A 24-year-old presents distressed by coarse hair on her chin, chest and lower abdomen that has worsened over three years. Her cycles are regular. She wants it gone — today. Your job is not to reach for the laser first: it is to score the hair objectively with the mFG, run a focused androgen panel, exclude the mimics (PCOS is commonest, but non-classic CAH and a tumour must be ruled out before labelling), and then walk the evidence-based ladder with a realistic 6-month timeline. The Endocrine Society 2018 guideline and the mFG score exist to stop doctors treating the symptom before they have characterised it.[1][6]

Overview and definition

Hirsutism is the presence of excess terminal (coarse, pigmented, androgen-responsive) hair in women in areas where it is normally male-pattern — the face, chest, abdomen and back. It is the principal clinical sign of androgen excess, affecting 5 to 15% of reproductive-age women, and is distinct from hypertrichosis, a generalised, non-androgen-mediated increase in fine vellus hair that is not driven by androgens and does not respond to anti-androgen therapy.[6][11]

The clinical distinction that changes the workup is hirsutism versus virilisation. Hirsutism reflects mild-to-moderate androgen excess (typical of PCOS and idiopathic hirsutism). Virilisation — clitoromegaly, voice deepening, frontal balding, increased muscle bulk, breast atrophy — reflects marked androgen excess and substantially raises the suspicion of an androgen-secreting tumour. A woman who is hirsute is one clinical problem; a woman who is virilised is another, and the tempo of her presentation matters.[1][11]