Excessive Hair Growth (Hypertrichosis & Hirsutism) 

1. Hypertrichosis (Non-Androgen Dependent)

Hypertrichosis is excessive hair growth in areas not typically sensitive to androgens.

• Onset: Since birth/early childhood (congenital) or later in life (acquired).

• Acquired Triggers: Drugs (Minoxidil, Cyclosporine, Phenytoin), Systemic Disease (Hypothyroidism, Porphyria Cutanea Tarda, Malnutrition), or Paraneoplastic (sudden acquired lanugo hair to rule out malignancy).

• Impact: Significant psychological distress due to visible hair growth.

• Skin of Colour Note: Excessive dark hair is highly visible on darker skin, increasing the cosmetic burden.

2. Hirsutism (Androgen Dependent)

Hirsutism is male-pattern terminal hair growth in women (face, chest, abdomen, back), driven by excess androgens.

• Onset & Tempo: Gradual onset around puberty suggests PCOS or Idiopathic Hirsutism. Rapid onset, severe growth, with virilisation suggests an androgen-secreting tumour (urgent investigation needed).

• Pattern: Assessed by the Ferriman–Gallwey score (>8 is abnormal).

• Associated Symptoms: Menstrual irregularities (oligo-/amenorrhoea), acne, weight gain, or signs of Virilisation (deep voice, clitoromegaly).

• Underlying Cause: PCOS (Polycystic Ovary Syndrome) is the most common cause (>75% of cases).

1. Hypertrichosis (Non-Androgen Dependent)

• Distribution: Generalised (entire body) or localised (e.g., "faun tail" on lower back).

• Hair Type: Lanugo (fine), Vellus (soft), or Terminal (thick, dark).

• Faun Tail Sign: Dense terminal hair over the lumbosacral area is a clue for underlying spinal dysraphism (requires imaging).

• Skin of Colour Note: Look for Post-Inflammatory Hyperpigmentation (PIH) from prior hair removal methods.

2. Hirsutism (Androgen Dependent)

• Score Hair: Use the Ferriman–Gallwey score (9 body areas, 0–4 each).

• Systemic Clues: Look for Acanthosis Nigricans (suggests insulin resistance/PCOS) and Cushingoid features.

• Investigations: Blood tests (Total Testosterone, DHEAS) and imaging (pelvic ultrasound for PCOS) to rule out serious causes.

1. Hypertrichosis (Non-Androgen Dependent)

1. Treat the Cause: Stop culprit drugs; screen for systemic disease/malignancy.

2. Hair Removal (Symptomatic):

• Permanent/Long-term: Laser Hair Reduction is the mainstay.6 For skin of colour (Fitzpatrick IV–VI), longer wavelengths are preferred to minimize PIH risk.

• Counsel about the higher risk of PIH, hypopigmentation, and keloid scarring from laser and electrolysis in darker skin types; emphasize an experienced practitioner.

2. Hirsutism (Androgen Dependent)

1. Treat Underlying Cause: Weight loss/Metformin for PCOS; surgery for tumours.

2. Pharmacologic Treatment (First-line):

• Combined Oral Contraceptives (COCPs): Often with anti-androgenic progestins (cyproterone) to suppress androgens.

• Antiandrogens (Add-on): Spironolactone (androgen receptor blocker), used with COCPs to prevent teratogenicity.

3. Cosmetic Hair Removal: Used alongside hormonal treatment. Long-wavelength lasers (Nd:YAG) are preferred for darker skin.

Hypertrichosis – StatPearls (NCBI Bookshelf): https://www.ncbi.nlm.nih.com/books/NBK534854/

Hypertrichosis – DermNet NZ: https://dermnetnz.org/topics/hypertrichosis

Hirsutism – StatPearls (NCBI Bookshelf): https://www.ncbi.nlm.nih.com/books/NBK470417/

Hirsutism – DermNet NZ: https://dermnetnz.org/topics/hirsutism