What is the workup for hirsutism (excessive hair growth) in women?

Workup for Hirsutism in Women

Begin by assessing the distribution and severity of hair growth using the Ferriman-Gallwey scoring system, obtain a focused history targeting menstrual irregularities and signs of hyperandrogenism, then measure serum total or free testosterone and DHEAS to identify the underlying cause. 1

Clinical Assessment

History and Physical Examination

Focus your history on these specific elements:

• Menstrual history: Document cycle regularity, oligomenorrhea, or amenorrhea, as these suggest PCOS (the cause of 70-80% of hirsutism cases) 1
• Onset and progression: Rapid onset over a few months suggests androgen-secreting tumor and requires urgent evaluation 2
• Associated symptoms: Ask specifically about acne, androgenic alopecia, clitoromegaly, and deepening voice (signs of virilization) 1, 3
• Signs of insulin resistance: Look for obesity, acanthosis nigricans, and truncal obesity 1
• Family history: Document similar conditions in relatives, as PCOS has familial clustering 1
• Medication history: Review for exogenous androgens and certain antiepileptic drugs 1

Physical Examination

Perform these specific assessments:

• Ferriman-Gallwey scoring: Quantify terminal hair growth in nine androgen-sensitive body areas to objectively document severity 2, 4
• Signs of virilization: Examine for clitoromegaly, male-pattern baldness, increased muscle mass, and voice changes 1, 3
• Metabolic markers: Calculate BMI and examine for acanthosis nigricans 1
• Pelvic examination: Assess for adnexal masses that might suggest ovarian tumors 5

Laboratory Testing

Initial Hormonal Evaluation

Order these tests for all women with abnormal Ferriman-Gallwey scores:

• Total testosterone or bioavailable/free testosterone: This is the primary screening test 1, 2
  • Levels >200 ng/dL (5.2 nmol/L) are highly suggestive of androgen-secreting tumor and require immediate imaging 1, 6, 3
  • Levels >150 ng/dL should prompt further investigation to exclude tumors 6
• DHEAS (dehydroepiandrosterone sulfate): Elevated levels suggest adrenal source of androgens 1, 2
• Androstenedione: Additional marker of androgen excess 1

Additional Endocrine Testing

Based on clinical presentation, consider:

• Thyroid-stimulating hormone (TSH): Screen for thyroid disorders that can contribute to hirsutism 1, 2
• Prolactin: Elevated levels suggest hyperprolactinemia as a cause 1, 2
• Glucose and insulin levels: Assess for insulin resistance, particularly in suspected PCOS 1
• 17-hydroxyprogesterone: If non-classical congenital adrenal hyperplasia (21-hydroxylase deficiency) is suspected 1, 2
• Luteinizing hormone (LH) and follicle-stimulating hormone (FSH): May show elevated LH:FSH ratio in PCOS 5, 1

Important caveat: Routine endocrinologic testing is not indicated for mild hirsutism without other signs of hyperandrogenism 5. However, patients with hirsutism plus oligomenorrhea, infertility, clitoromegaly, or truncal obesity warrant full endocrine evaluation 5.

Imaging Studies

Pelvic Ultrasound

Obtain transvaginal ultrasound when PCOS is suspected:

• Diagnostic criteria: Look for >10 peripheral cysts (2-8 mm diameter) with thickened ovarian stroma 1
• Timing: This confirms polycystic ovarian morphology in women meeting clinical and biochemical criteria for PCOS 1

Adrenal and Ovarian Imaging

Order CT or MRI of adrenals and pelvis when:

• Total testosterone >200 ng/dL 1, 6
• Rapid onset of symptoms over weeks to months 2
• Signs of virilization are present 3, 2
• DHEAS is markedly elevated (suggesting adrenal tumor) 2

Diagnostic Algorithm

Step 1: Assess severity with Ferriman-Gallwey scoring and obtain focused history 2, 4

Step 2: Measure total or free testosterone and DHEAS in all women with abnormal scores 1, 2

Step 3: If testosterone >200 ng/dL or rapid onset/virilization present, obtain immediate imaging to exclude tumor 1, 6, 2

Step 4: If testosterone mildly elevated with menstrual irregularities, obtain pelvic ultrasound and additional hormonal testing (TSH, prolactin, glucose/insulin) to diagnose PCOS 1

Step 5: If testosterone normal with hirsutism, diagnose idiopathic hirsutism (accounts for significant proportion of cases along with PCOS) 1, 2, 4

Step 6: Consider 17-hydroxyprogesterone testing if family history or ethnic background suggests non-classical CAH 1, 2

Common Pitfalls

• Missing androgen-secreting tumors: Always measure testosterone levels; do not rely on clinical assessment alone, as tumors require immediate intervention 6, 4
• Overlooking medication-induced hirsutism: Specifically ask about antiepileptic drugs and exogenous androgens 1
• Inadequate assessment in adolescents: PCOS may present during adolescence and benefits from early intervention 1
• Ignoring metabolic complications: Women with PCOS-related hirsutism have increased risk of insulin resistance and metabolic syndrome requiring screening 1