What is the common cause of hirsutism (excessive hair growth) on the chin in women?

Common Causes of Hair on Chin in Women

Polycystic ovary syndrome (PCOS) is the most common cause of hirsutism (excessive hair growth) on the chin in women, accounting for 70-80% of cases. 1

Understanding Hirsutism

Hirsutism refers to excessive terminal (coarse) hair growth in women in a male-like pattern, particularly in androgen-dependent areas such as the chin, upper lip, chest, and lower abdomen. It affects approximately 5-15% of women and is usually a sign of underlying androgen excess 2.

Common Causes of Hirsutism

• Polycystic Ovary Syndrome (PCOS): The predominant cause (70-80% of hirsutism cases), characterized by hyperandrogenism, chronic anovulation, and often insulin resistance 1
• Idiopathic Hirsutism: Accounts for 5-17% of cases, with normal ovulatory function and androgen levels 3
• Non-classical congenital adrenal hyperplasia: Responsible for approximately 1-8% of hirsutism cases, most commonly due to 21-hydroxylase deficiency 3
• Androgen-secreting tumors: Rare but serious cause, suggested by total testosterone levels >200 ng/dL 1
• Medications: Certain drugs can cause hirsutism, including androgenic medications and some antiepileptics 1
• Other endocrine disorders: Less common causes include Cushing's syndrome, hyperprolactinemia, acromegaly, and thyroid disorders 3

Clinical Evaluation

When assessing hirsutism, particularly facial hair on the chin:

• Severity assessment: The modified Ferriman-Gallwey (mFG) scoring system is the standard for evaluating hirsutism severity 4
• Pattern and progression: Rapid onset of hirsutism over a few months or signs of virilization (deepening voice, increased muscle mass, clitoromegaly) suggests an androgen-secreting tumor 5
• Associated symptoms: Look for menstrual irregularities, acne, androgenic alopecia, obesity, and acanthosis nigricans (suggestive of insulin resistance) 1

Diagnostic Approach

For women with excessive chin hair and suspected hirsutism:

• Initial testing: Serum total testosterone should be obtained in premenopausal women with an mFG score ≥8 4
• Additional testing: If total testosterone is normal but hirsutism is moderate to severe, measure free testosterone and early morning total testosterone 4
• Further evaluation: For elevated testosterone levels, additional testing may include DHEAS, androstenedione, glucose/insulin levels, thyroid function tests, and prolactin 1
• Imaging: Pelvic ultrasound may detect polycystic ovaries in women with PCOS-related hirsutism 1

Treatment Options

Treatment should be tailored based on the underlying cause:

• Hormonal suppression: Combined oral contraceptives are first-line therapy for PCOS-related hirsutism 5
• Anti-androgens: Medications such as spironolactone, flutamide, finasteride, and cyproterone acetate can effectively reduce hirsutism 1, 6
• Topical treatments: Eflornithine hydrochloride 13.9% cream can slow facial hair growth 2
• Hair removal methods: Options include temporary methods (shaving, waxing, plucking) and more permanent solutions (electrolysis, laser hair removal) 5
• Lifestyle modifications: Weight loss of at least 5% can improve metabolic and reproductive abnormalities in obese women with PCOS 7
• Insulin sensitizers: Metformin may help improve ovulation and reduce androgen levels in women with PCOS 1

Special Considerations

• Treatment should be continued for at least six months before evaluating efficacy due to the length of the hair growth cycle 5
• Local androgen production in hair follicles means that circulating androgen levels don't always correlate with the severity of hirsutism 6
• There is a strong genetic component to hirsutism, with familial predisposition to both the underlying disorders and factors regulating hair growth 2

When to Refer

Consider referral to an endocrinologist when:

• Total testosterone levels are markedly elevated (>200 ng/dL) 1
• Rapid onset of hirsutism or signs of virilization are present 5
• Standard treatments are ineffective after 6-12 months 5