What is the approach to assessing hirsutism?

Approach to Assessment of Excessive Hair Growth (Hirsutism)

Definition

Hirsutism is the presence of terminal (coarse) hair growth in androgen-dependent areas of the body in a male-like distribution pattern in women, affecting 5-15% of women globally. 1, 2

• Terminal hair growth occurs in nine key body sites: upper lip, chin, chest, upper and lower back, upper and lower abdomen, upper arms, and thighs 2
• Distinguished from hypertrichosis, which is excessive hair growth beyond normal variation for age, sex, or race in any body area 3

Classification

Hirsutism severity is quantified using the modified Ferriman-Gallwey (mFG) score, with scores ≥4-6 (varying by ethnicity) defining hirsutism, and scores ≥8 indicating abnormal hirsutism requiring evaluation. 2, 3

• Mild hirsutism: mFG score 8-15 4
• Moderate hirsutism: mFG score 16-25 4
• Severe hirsutism: mFG score >25 4

Differential Diagnosis

Most Common Causes (>95% of cases):

• Polycystic ovary syndrome (PCOS): 70-90% of hirsutism cases, characterized by hyperandrogenic chronic anovulation, insulin resistance, and hyperinsulinemia 5, 1, 2
• Idiopathic hirsutism: 5-10% of cases, with normal ovulatory function and normal androgen levels 1, 2
• Non-classical congenital adrenal hyperplasia (21-hydroxylase deficiency): 1-10% depending on ethnicity 5, 2

Rare but Critical Causes:

• Androgen-secreting tumors (ovarian or adrenal): Suggested by total testosterone >200 ng/dL 5, 6
• Cushing's syndrome 5, 2
• Acromegaly 2
• Medication-induced: Exogenous androgens, certain antiepileptic drugs, androgenic progestins (norethisterone derivatives, levonorgestrel) 5, 1
• Ovarian hyperthecosis 2
• Syndromes of severe insulin resistance/lipodystrophy 2

History

Character of Hair Growth:

• Duration and rate of onset: Rapid onset suggests androgen-secreting tumor 1, 6
• Distribution pattern: Document specific body areas affected using mFG scoring system 2, 3
• Severity and progression: Assess patient's perception of distress regardless of observable severity 2

Red Flags (Virilization):

• Clitoromegaly 5, 6
• Deepening voice 6
• Male-pattern balding 5, 6
• Increased muscle mass 6
• Breast atrophy 6
• Rapid progression of symptoms 6

Risk Factors and Associated Features:

• Menstrual history: Oligomenorrhea, amenorrhea, or irregular cycles suggest PCOS 5, 1
• Infertility or anovulation 1, 4
• Acne, particularly severe or treatment-resistant 5, 6
• Signs of insulin resistance: Obesity, acanthosis nigricans 5, 1
• Family history: Similar conditions in relatives (strong genetic component) 1
• Medication history: Current or recent use of androgens, antiepileptics, or androgenic contraceptives 5, 1
• Symptoms of Cushing's syndrome: Weight gain, striae, easy bruising, proximal muscle weakness 6
• Symptoms of acromegaly: Headaches, visual changes, joint pain, excessive sweating 7

Physical Examination

Focused Assessment:

• Modified Ferriman-Gallwey scoring: Systematically assess all nine body sites for terminal hair growth 2, 3
• Signs of virilization: Examine for clitoromegaly, male-pattern balding, increased muscle mass 5, 6
• Acne distribution and severity 5
• Acanthosis nigricans: Velvety hyperpigmentation in skin folds indicating insulin resistance 5, 1
• Body mass index and waist circumference: Assess for obesity and central adiposity 4
• Pelvic examination: Assess for adnexal masses suggesting ovarian tumors 5, 8
• Cushingoid features: Moon facies, buffalo hump, central obesity, purple striae 6
• Acromegalic features: Coarse facial features, enlarged hands/feet, prognathism 7
• Thyroid examination: Assess for goiter or nodules 1

Investigations

Initial Laboratory Testing:

For premenopausal patients with mFG score ≥8, obtain serum total testosterone as the initial test. 3

• Total testosterone or bioavailable/free testosterone:
  • Normal range: Reassuring but does not exclude PCOS 5, 3

  • 200 ng/dL: Highly suggestive of androgen-secreting tumor, requires urgent imaging 5, 6

  • Moderately elevated (50-200 ng/dL): Consistent with PCOS or non-classical CAH 6

Extended Hormonal Panel (if initial testosterone normal but moderate-severe hirsutism present):

• Early morning serum total testosterone and free testosterone 3
• DHEAS (dehydroepiandrosterone sulfate): Elevated levels suggest adrenal source of androgens 5, 6
• Androstenedione: May be elevated in PCOS or adrenal disorders 5
• 17-hydroxyprogesterone (early morning, follicular phase): Elevated >200 ng/dL suggests non-classical CAH; if 200-800 ng/dL, perform ACTH stimulation test 6
• Prolactin: Exclude hyperprolactinemia 5, 1
• Thyroid-stimulating hormone (TSH): Exclude thyroid dysfunction 5, 1

Metabolic Assessment (especially if PCOS suspected):

• Fasting glucose and insulin or 2-hour oral glucose tolerance test: Assess for insulin resistance and diabetes 5, 1
• Lipid panel: Assess cardiovascular risk 4

Imaging Studies:

• Pelvic ultrasound: Indicated if PCOS suspected; look for >10 peripheral cysts (2-8 mm diameter) with thickened ovarian stroma 5
• Adrenal and pelvic CT or MRI: Indicated if testosterone >200 ng/dL or DHEAS markedly elevated to localize androgen-secreting tumor 6

Expected Findings by Diagnosis:

• PCOS: Elevated testosterone/free testosterone, elevated androstenedione, polycystic ovaries on ultrasound, evidence of insulin resistance 5, 4
• Non-classical CAH: Elevated 17-hydroxyprogesterone (>200 ng/dL baseline or exaggerated ACTH stimulation response) 6
• Androgen-secreting tumor: Testosterone >200 ng/dL, discrete mass on imaging 5, 6
• Idiopathic hirsutism: Normal androgen levels, normal ovulatory function 1, 2

Empiric Treatment

First-Line Therapy:

Combined oral contraceptives (OCPs) are first-line therapy for PCOS-related hirsutism to suppress ovarian androgen production; avoid OCPs containing androgenic progestins (norethisterone derivatives, levonorgestrel). 5

• OCPs should be continued for at least 6-12 months before assessing efficacy 4
• Contraindicated in women with cardiovascular risk factors, thromboembolism history, or metabolic comorbidities 4

Second-Line Medical Therapy:

Anti-androgen medications (spironolactone, flutamide, finasteride, cyproterone acetate) provide peripheral androgen blockade and should be combined with OCPs or reliable contraception due to teratogenicity. 5, 1

• Spironolactone: Most commonly used anti-androgen in North America 1, 4
• Requires 6-12 months of treatment for visible improvement 4

Alternative Hormonal Suppression (if OCPs contraindicated):

• Metformin plus lifestyle modifications: For women with insulin resistance and metabolic comorbidities 5, 4
• Weight loss: 5% weight reduction improves metabolic and reproductive abnormalities in obese women with PCOS 5

Cosmetic and Mechanical Treatments:

• Topical eflornithine hydrochloride 13.9% cream: Slows facial hair growth 5, 1
• Hair removal techniques: Shaving, waxing, plucking, electrolysis, laser therapy 5, 1
• Combination therapy is most effective: Medical therapy plus mechanical hair removal 2, 4

Treatment Algorithm by Severity:

• Mild hirsutism (mFG 8-15): OCPs plus cosmetic/mechanical methods 4
• Moderate-severe hirsutism (mFG >15): OCPs plus anti-androgens, or anti-androgens plus reliable contraception if OCPs contraindicated 4
• Idiopathic hirsutism: Same treatment approach as PCOS-related hirsutism 1

Indications to Refer

Urgent Gynecology/Endocrinology Referral:

• Testosterone >200 ng/dL: Suspect androgen-secreting tumor, requires urgent imaging and surgical evaluation 5, 6
• Signs of virilization: Clitoromegaly, deepening voice, rapid progression 6
• Adnexal mass on examination or imaging 5, 8

Routine Endocrinology Referral:

• Suspected non-classical CAH: Elevated 17-hydroxyprogesterone requiring ACTH stimulation testing 6, 3
• Suspected Cushing's syndrome or acromegaly 6, 3
• Hirsutism unresponsive to first-line therapy after 6-12 months 4, 3
• Complex metabolic comorbidities requiring specialized management 4

Gynecology Referral:

• Infertility: Failure to conceive after 12 months (or 6 months if age >35 years) 8
• Amenorrhea or severe oligomenorrhea unresponsive to treatment 8
• Abnormal uterine bleeding with severe anemia 8

Dermatology Referral:

• Severe acne unresponsive to standard therapy 3
• Guidance on advanced hair removal techniques (laser, electrolysis) 3

Critical Pitfalls

Diagnostic Pitfalls:

• Do not dismiss patient complaints based on examination findings: Women who complain of excess unwanted hair growth should be evaluated regardless of observable severity on examination 2
• Do not underestimate patient distress: Hirsutism has significant psychosocial impact and quality of life implications 1, 2
• Do not miss androgen-secreting tumors: Always measure testosterone in women with rapid onset, severe hirsutism, or virilization 5, 6
• Do not overlook ethnic variation: Diagnostic mFG cutoffs vary by ethnicity; Asian women may have lower prevalence of hirsutism despite androgen excess 1, 2
• Do not perform routine endocrine testing for mild hirsutism without other signs of hyperandrogenism: Reserve full evaluation for mFG ≥8 or presence of oligomenorrhea, infertility, clitoromegaly, or truncal obesity 5

Treatment Pitfalls:

• Do not prescribe OCPs containing androgenic progestins: Norethisterone derivatives and levonorgestrel can worsen hirsutism 5
• Do not prescribe anti-androgens without reliable contraception: All anti-androgens are teratogenic and require effective contraception 1, 4
• Do not expect rapid results: Medical therapy requires 6-12 months for visible improvement; counsel patients on realistic timelines 4
• Do not use monotherapy when combination therapy is more effective: Combine medical therapy with mechanical hair removal for optimal results 2, 4
• Do not forget metabolic screening in PCOS: Screen for diabetes, dyslipidemia, and cardiovascular risk factors 5, 4

Follow-up Pitfalls:

• Do not abandon patients with idiopathic hirsutism: Treatment approach is the same as for PCOS-related hirsutism despite normal androgen levels 1, 2
• Do not fail to provide strong clinical support: Treatment adherence is crucial for success and requires ongoing encouragement 4
• Do not ignore treatment failure: Hirsutism unresponsive to 6-12 months of appropriate therapy warrants endocrinology referral 4, 3