What is the assessment and treatment approach for hirsutism, including the use of the Ferriman-Gallwey (FG) score?

Assessment of Hirsutism Using the Ferriman-Gallwey Score

The modified Ferriman-Gallwey (mFG) score is the standardized clinical tool for quantifying hirsutism, assessing terminal hair growth at nine body sites (upper lip, chin, chest, upper and lower back, upper and lower abdomen, upper arms, and thighs), with hirsutism typically defined as an mFG score >4-6, though ethnic variations must be considered. 1, 2

Clinical Assessment Framework

Visual Scoring System

• The mFG score evaluates terminal hair density at nine anatomical sites, with each site scored from 0 (no terminal hair) to 4 (extensive terminal hair growth) 1, 2
• A score of 0 indicates no terminal hair, 1 indicates minimal growth, 2 indicates more than minimal but less than half the area covered, 3 indicates more than half covered, and 4 indicates complete coverage 3
• The diagnostic threshold varies by ethnicity: scores >4-6 generally indicate hirsutism in most populations, but lower cutoffs may be appropriate for Asian women and higher cutoffs for Mediterranean or Middle Eastern women 1, 2

Key Assessment Principles

• Evaluate all nine body sites systematically during physical examination, as patient-reported excess hair growth warrants full evaluation regardless of observable severity on examination 1
• Document baseline mFG score before initiating treatment to enable objective monitoring of therapeutic response 4, 3
• Assess menstrual regularity, as cycle disturbances combined with hirsutism warrant investigation for underlying endocrine disorders 4

Diagnostic Evaluation

Clinical History Elements

• Determine onset and progression: functional causes (PCOS, idiopathic hirsutism) begin peripubertally and progress slowly, whereas androgen-secreting neoplasms have sudden onset and rapid progression 3
• Assess for virilization signs (clitoromegaly, voice deepening, male-pattern baldness, increased muscle mass) which suggest more severe androgen excess or neoplasm 3
• Document medication history, as certain drugs can induce hirsutism 1
• Evaluate degree of patient distress, as this guides treatment intensity independent of objective mFG score 1, 5

Laboratory Investigation

• Measure total testosterone: levels >2.5 nmol/L suggest PCOS or other pathology 4
• Obtain androstenedione levels: values >10.0 nmol/L warrant evaluation for adrenal or ovarian tumor 4
• Check DHEAS to rule out non-classical congenital adrenal hyperplasia: age-specific cutoffs apply (>3800 ng/mL for ages 20-29, >2700 ng/mL for ages 30-39) 4
• Measure LH and FSH on days 3-6 of cycle: LH/FSH ratio >2 suggests PCOS 4
• Importantly, androgen levels correlate poorly with hirsutism severity, and some women with PCOS and hirsutism have normal biochemical androgen levels, presenting diagnostic challenges 2

Additional Testing

• Perform pelvic ultrasonography (transvaginal preferred) if clinical features or hormonal tests suggest ovarian pathology: >10 peripheral cysts of 2-8 mm diameter with thickened stroma indicates polycystic ovaries 4
• Consider pituitary MRI if galactorrhea or hyperprolactinemia present 4

Underlying Etiologies

Common Causes

• PCOS accounts for 80-90% of hirsutism cases, characterized by androgen excess and individual pilosebaceous unit sensitivity to androgens 1, 5
• Idiopathic hirsutism represents 5-10% of cases, with normal ovulatory function and androgen levels but increased peripheral androgen sensitivity 1
• Non-classic 21-hydroxylase deficient adrenal hyperplasia accounts for 1-10% depending on ethnicity 1

Rare Causes Requiring Exclusion

• Androgen-secreting ovarian or adrenal neoplasms (suspect with rapid onset, virilization, very high androgens) 1, 3
• Cushing syndrome (assess for weight gain, proximal muscle weakness, hypertension, purple striae, buffalo hump) 4
• Acromegaly 1
• Syndromes of severe insulin resistance or lipodystrophy 1
• Ovarian hyperthecosis 1

Treatment Approach Based on Severity

Mild Hirsutism (mFG 8-15)

• Combine non-pharmacological hair removal methods (laser, electrolysis, waxing) with combined oral contraceptives (COCs) to suppress ovarian androgen production 5
• COCs containing cyproterone acetate 2 mg/ethinylestradiol 35 μg or drospirenone 3 mg/ethinylestradiol 20 μg are effective options 4

Moderate to Severe Hirsutism (mFG >15)

• Combine antiandrogens (spironolactone, cyproterone acetate, or finasteride) with COCs for synergistic effect 5
• If COCs contraindicated due to metabolic comorbidities, use metformin with lifestyle modifications as second-line for androgen suppression, plus antiandrogen with reliable contraception 5
• Maintain treatment for minimum 6-12 months, as hair growth cycles require prolonged therapy for visible improvement 5, 3

Special Considerations

• In women with PCOS and metabolic comorbidities (obesity, insulin resistance), lifestyle interventions reducing weight by ≥5% improve hirsutism (mean difference in mFG score -1.19), testosterone levels, and metabolic parameters 4
• Screen for cardiovascular risk factors (blood pressure, lipids, HbA1c) in all women with PCOS and hirsutism 4
• Assess for depression and anxiety, as hirsutism significantly impacts quality of life 1

Critical Pitfalls to Avoid

• Do not dismiss patient concerns about excess hair growth based solely on low mFG scores—patient distress and self-perception are valid treatment indications 1
• Do not rely exclusively on androgen levels to diagnose or exclude hyperandrogenism, as correlation with hirsutism severity is poor 2
• Do not overlook ethnic variations in mFG score interpretation—apply population-appropriate cutoffs 1, 2
• Do not fail to investigate rapidly progressive hirsutism with virilization, as this suggests androgen-secreting neoplasm requiring urgent evaluation 3
• Do not expect rapid treatment response—counsel patients that 6-12 months of consistent therapy is required before significant improvement 5, 3