How should I evaluate and manage a woman with diffuse hair thinning (female pattern alopecia)?

Evaluation and Management of Female Pattern Hair Loss (Diffuse Hair Thinning)

Initial Clinical Assessment

Begin with dermoscopy to distinguish female pattern alopecia from telogen effluvium and alopecia areata—this single non-invasive tool can eliminate the need for scalp biopsy in most cases. 1

Key Clinical Features to Document

• Pattern of hair loss: Diffuse thinning over the central scalp with preserved frontal hairline indicates female pattern alopecia (Ludwig pattern), whereas discrete patches with exclamation-mark hairs suggest alopecia areata 1, 2

• Dermoscopic findings: Female pattern alopecia shows normal follicular openings without yellow dots, exclamation-mark hairs, or cadaverized hairs—features that would indicate alopecia areata 1, 3

• Onset and duration: Sudden diffuse shedding over days to weeks suggests telogen effluvium, while gradual progressive thinning over months to years indicates female pattern alopecia 3, 4

• Signs of hyperandrogenism: Check for acne, hirsutism, irregular menses, or infertility—these suggest polycystic ovary syndrome (PCOS) as an underlying cause 4, 5

Laboratory Testing Strategy

Order a targeted panel only when the diagnosis is uncertain or signs of systemic disease are present—routine extensive testing adds cost without clinical benefit. 6, 1

Essential Laboratory Tests

• Serum ferritin: Target ≥60 ng/mL for optimal hair growth; iron deficiency is the most common nutritional cause of diffuse hair loss 1, 3

• TSH and free T4: Thyroid dysfunction frequently manifests as diffuse hair loss 1, 3

• 25-OH vitamin D: 70% of alopecia areata patients have levels <20 ng/mL; vitamin D is essential for hair follicle cycling 1, 3

• Serum zinc: Levels tend to be lower in patients with hair loss 1, 3

Additional Tests When Hyperandrogenism Is Suspected

• Total testosterone or free testosterone with SHBG: Order only if acne, hirsutism, or irregular periods are present 1

• Consider PCOS evaluation: Two-hour oral glucose tolerance test and fasting lipid panel if insulin resistance or metabolic syndrome is suspected 1

Tests to Avoid

• Do not order extensive autoimmune panels for straightforward female pattern alopecia—the yield is extremely low 6, 1, 2

• Fungal culture is indicated only if scalp inflammation or scaling suggests tinea capitis 6, 1, 3

• Scalp biopsy is reserved for cases where the diagnosis remains uncertain after clinical examination and dermoscopy 6, 1, 3

Treatment Algorithm

First-Line Therapy

Initiate topical minoxidil 2% solution 1 mL applied twice daily to the affected scalp—this is the only FDA-approved treatment for female pattern alopecia and should be continued for a minimum of 12 months before assessing efficacy. 4, 7

• Minoxidil arrests progression rather than stimulates dramatic regrowth 2

• Treatment must be continuous; stopping will result in resumption of hair loss 2

• Counsel patients that visible improvement is unlikely within the first 3 months 2, 3

Adjunctive Therapy for Inadequate Response

If minoxidil alone produces inadequate results after 6 months, add platelet-rich plasma (PRP) injections: 3–5 sessions at 1-month intervals, then maintenance every 6 months. 2

• PRP increases hair density and follicle diameter by inducing dermal papilla proliferation and accelerating telogen-to-anagen transition 2

Treatment for Hyperandrogenic Female Pattern Alopecia

When PCOS or elevated androgens are documented, add oral antiandrogen therapy:

• Spironolactone (antiandrogen) combined with oral contraceptives containing ethinylestradiol 8, 7

• Cyproterone acetate with tricyclic contraceptives is the preferred antiandrogen in reproductive-aged women 8

• Finasteride 2.5 mg daily may be considered in postmenopausal women or those with documented androgen excess 8, 7

Nutritional Supplementation Based on Laboratory Results

• Iron supplementation if ferritin <60 ng/mL to reach optimal levels 1, 3

• Vitamin D supplementation if 25-OH vitamin D <20 ng/mL per adult guidelines 1, 3

• Zinc supplementation if serum zinc is low 1, 3

• Thyroid hormone replacement if TSH is elevated with low free T4 1, 3

Alternative Options

• Hair transplantation is the only permanent solution but requires surgical procedures 7, 9

• Wigs or hairpieces provide immediate cosmetic benefit for extensive hair loss 6, 2

Common Pitfalls to Avoid

• Do not confuse telogen effluvium with female pattern alopecia: Telogen effluvium presents with sudden clumping of hairs on the pillow and while combing, whereas female pattern alopecia shows gradual progressive thinning 3

• Do not overlook the psychological impact: Hair loss can cause profound distress, anxiety, and depression—screen for mental health concerns and provide referral when needed 6, 1, 2

• Do not prescribe minoxidil for acute telogen effluvium: It is indicated for androgenetic alopecia, not stress-related shedding 3

• Avoid potent topical corticosteroids: They lack convincing efficacy evidence for female pattern alopecia 6, 2

• Do not promise permanent cure: Current treatments slow progression and may induce temporary regrowth but do not alter the long-term natural history of the disease 6, 2

Management of Expectations

• Early initiation of treatment and combination of modalities are more efficacious than monotherapy 9

• The aim of therapy is to slow or stop disease progression—patients should understand that dramatic regrowth is unlikely 7

• Weight loss improves hair loss in hyperandrogenic women 8