What are the causes of hair loss in a postmenopausal woman and how should it be evaluated and managed?

Postmenopausal Hair Loss: Causes, Evaluation, and Management

Primary Causes

Postmenopausal hair loss results primarily from declining estrogen levels that disrupt the hair follicle cycle, with female pattern hair loss (FPHL) affecting over 50% of postmenopausal women. 1

Hormonal Mechanisms

• Estrogen deficiency directly impacts hair follicles, which are estrogen-sensitive tissues, leading to decreased anagen (growth phase) hairs, reduced hair density, decreased caliber, and altered texture 2, 3
• Relative androgen excess occurs as ovarian estrogen production ceases while androgen levels remain relatively stable, causing miniaturization of hair follicles and decreased anagen-to-telogen ratio 4, 5
• Hormonal fluctuations begin up to 10 years before menopause during the perimenopausal transition, with progressive worsening after menopause 3

Clinical Patterns

Two distinct patterns emerge in postmenopausal women 5:

1. Diffuse generalized hair loss (most common, 26% of women):

   • Correlates with older age and body hair loss 5
   • Represents the typical pattern of age-related hormonal decline 5

2. Frontal hair loss (9% of women):

   • Associated with relatively younger age and higher facial hair scores 5
   • May indicate more pronounced androgen effects 5

Specific Hair Disorders

• Female pattern hair loss (FPHL): Prevalence of 52.2% in postmenopausal women aged 50-65 years, with 73.2% classified as Ludwig grade I, 22.6% as grade II, and 4.3% as grade III 1
• Frontal fibrosing alopecia: Increased frequency in perimenopausal and postmenopausal states 2, 3
• Telogen effluvium: More common during menopausal transition 3

Risk Factors

Body mass index ≥25 kg/m² significantly increases FPHL risk (adjusted OR = 2.65) after controlling for age and family history. 1

Additional risk factors include:

• Increasing age and time since menopause 1
• Family history of hair loss 1
• Endocrine therapy with aromatase inhibitors (causes grade 1 alopecia primarily on crown with frontal/bitemporal recession, developing 6-18 months after initiation) 4

Evaluation Approach

Laboratory Testing

Exclude secondary causes through targeted laboratory evaluation: 4, 6

• Thyroid function: TSH and free T4 to rule out thyroid disorders 4, 6
• Iron stores: Serum ferritin (though routine screening not recommended per alopecia areata guidelines, consider in appropriate clinical context) 4
• Vitamin D and zinc levels 4
• Hormonal assessment: Consider if clinical features suggest hyperandrogenism 4

Clinical Examination

• Assess pattern and distribution: diffuse vs. frontal vs. patchy 4, 5
• Evaluate for concurrent facial hirsutism (39% of postmenopausal women report facial hair gain, most commonly on chin at 32%) 5
• Examine for body hair changes (body hair loss correlates with older age and androgen-sensitive sites) 5
• Rule out differential diagnoses: trichotillomania, tinea capitis, scarring alopecia, telogen effluvium, systemic lupus erythematosus 4

Dermoscopy

• Useful for confirming diagnosis and assessing activity 4
• Can identify miniaturization patterns characteristic of androgenetic changes 4

Management Considerations

Iatrogenic Causes

Women receiving aromatase inhibitors for breast cancer require monitoring for endocrine therapy-induced alopecia (EIA), which affects 4.4-25% of patients and causes 8% to discontinue therapy. 4, 6

• EIA presents as grade 1 alopecia on crown with frontal/bitemporal recession 4
• Develops most prominently 6-18 months after therapy initiation 4
• Histologically shows follicular miniaturization and decreased anagen-to-telogen ratio 4

Psychosocial Impact

Hair loss significantly affects self-esteem, body image, and quality of life, with women reporting feelings of self-consciousness, embarrassment, stress, and anxiety. 4, 1

• Early detection and proper treatment may increase quality of life 1
• Consider referral to specialist menopause service for comprehensive management 4
• Address psychological effects as they may impact general health 4

Treatment Limitations

Current evidence supporting specific treatments for postmenopausal hair disorders remains limited, with most strategies being symptomatic and nonspecific. 7

• Avoid hazardous treatments of unproven efficacy, as hair loss has no direct impact on general health (though psychological effects are significant) 4
• Treatment decisions depend on severity, impact on daily living, and patient preferences 4

Key Clinical Pitfalls

• Do not assume all postmenopausal hair loss is physiologic: Always exclude thyroid disorders, iron deficiency, and other metabolic causes through appropriate laboratory testing 4, 6
• Recognize the high prevalence: With 52% of postmenopausal women affected, hair loss awareness should be integrated into menopause clinics 1
• Distinguish patterns: Frontal hair loss with hirsutism in younger postmenopausal women may indicate different pathophysiology than diffuse loss in older women 5
• Monitor endocrine therapy patients: Women on aromatase inhibitors require specific surveillance for EIA, which can paradoxically cause both scalp hair loss and facial hirsutism 4, 6