How should I evaluate and manage an adult with non‑scarring androgen‑dependent hair loss?

Evaluation and Management of Adult Non-Scarring Androgenetic Alopecia

Start treatment immediately with topical minoxidil 5% twice daily for men (or 2% for women) and oral finasteride 1 mg daily for men, as these are the only FDA-approved treatments proven to halt progression and stimulate regrowth in androgenetic alopecia. 1, 2

Initial Diagnostic Confirmation

Pattern Recognition is Key:

• Look for the characteristic Hamilton-Norwood pattern in men: temporal recession, vertex thinning, and mid-frontal scalp involvement with preserved occipital and lateral scalp hair 1, 3
• In women, identify the Ludwig pattern (central scalp thinning with preserved frontal hairline) or Christmas tree pattern (frontal accentuation) 4
• Confirm normal scalp appearance without inflammatory scaling—if scaling is present, this suggests seborrheic dermatitis, not androgenetic alopecia 4
• Use dermoscopy to identify miniaturized hairs, which are the hallmark of androgenetic alopecia 4, 3

Critical Differential Diagnosis:

• If hair loss is patchy rather than patterned, you are dealing with alopecia areata, which requires entirely different treatment (intralesional corticosteroids or contact immunotherapy) 5, 1
• Alopecia areata presents with exclamation mark hairs and yellow dots on dermoscopy—these are absent in androgenetic alopecia 5, 3
• Telogen effluvium causes diffuse shedding without the characteristic pattern and typically follows a physiologic stressor 6

Laboratory Evaluation

For Women—Mandatory Endocrine Workup:

• Measure free and total testosterone, DHEA-S, and androstenedione to assess for androgen excess 4, 7
• Check TSH and free T4 to rule out thyroid disease 4
• Measure serum ferritin (iron deficiency is common in women with hair loss), vitamin D, and zinc levels 4, 7
• If menstrual irregularities are present, add prolactin 4

For Men—Selective Testing Only:

• Routine laboratory testing is not recommended for typical male pattern baldness 5, 1
• Consider endocrine evaluation only if there are signs of androgen excess or atypical presentation 5

Treatment Algorithm

First-Line Pharmacological Treatment

For Men:

• Initiate combination therapy: Oral finasteride 1 mg daily plus topical minoxidil 5% twice daily 1, 2
• Finasteride works by inhibiting 5-alpha reductase, blocking conversion of testosterone to dihydrotestosterone 1
• Minoxidil 5% is applied directly to the scalp, 1 mL twice daily to affected areas 2
• Set realistic expectations: Results appear at 2-4 months minimum, with peak effect at 12 months 2, 8

For Women Without Hyperandrogenism:

• Start with topical minoxidil 5% twice daily (or 2% if 5% causes irritation) 4, 9
• Do not use finasteride in women of childbearing potential due to teratogenic risk 9

For Women With Documented Hyperandrogenism:

• Add oral antiandrogens (spironolactone or cyproterone acetate) to minoxidil 9, 10
• These work best when initiated early in the disease course 10

Adjunctive Therapy—Platelet-Rich Plasma (PRP)

Consider PRP for optimal results, especially with suboptimal response to medical therapy:

• Treatment phase: 3-5 sessions spaced exactly 1 month apart using 5-7 mL PRP per session 5, 1, 4
• Maintenance phase: 1 session every 6 months 5, 1, 4
• Inject at 90-degree angle, 2-4 mm depth, 1 cm apart in areas of hair loss 1
• Evidence shows PRP combined with minoxidil produces the highest increase in hair density compared to either treatment alone 4
• Higher platelet concentrations are more effective than lower concentrations 5

Monitoring Treatment Response

Use Objective Measures at Specific Intervals:

• Schedule formal evaluation at 3 months for minoxidil alone, 12 months for PRP combination therapy 4
• Take standardized before-and-after photographs at each visit 1, 4
• Use trichoscopy to measure hair density per cm² and hair shaft diameter 5, 4
• Perform hair pull test—fewer hairs coming out indicates improved hair strength 5
• Administer patient self-assessment questionnaires for satisfaction scores 1, 4

Positive Response Indicators:

• Increased hair density per cm² 5
• Increased hair shaft diameter 5, 4
• Decreased proportion of telogen hairs 4
• Improved patient satisfaction scores 1

Advanced Treatment Options

For Inadequate Response to Medical Therapy:

• Consider hair transplantation (follicular unit extraction) combined with PRP pre-treatment and follicle soaking 1
• Transplantation requires well-preserved occipital donor area 9
• Wigs provide immediate cosmetic benefit but are rarely natural-appearing for men 1

Critical Pitfalls to Avoid

Common Mistakes That Lead to Treatment Failure:

1. Premature discontinuation: Hair loss will return to pretreatment status if therapy is stopped—treatment must be lifelong 4, 10

2. Delaying effective treatment: Trying unproven supplements (like saw palmetto, which lacks robust data) while delaying finasteride and minoxidil may result in irreversible hair loss 1

3. Inadequate follow-up: Patients need regular monitoring at 3,6, and 12 months to assess response 4

4. Misdiagnosis: Using topical corticosteroids for androgenetic alopecia is ineffective—these are indicated only for alopecia areata 1

5. Unrealistic expectations: Warn patients about temporary increased shedding in the first 2 weeks of minoxidil use—this is expected as old hairs are shed to make way for new growth 2

6. Overlooking psychological impact: Hair loss causes reduced self-esteem, anxiety, and social dysfunction—consider counseling and cosmetic camouflage options 9, 10, 6

Special Considerations

Early Treatment is Critical:

• Both finasteride and minoxidil work best at arresting progression rather than stimulating regrowth 10, 8
• Treatment is more effective in patients with recent onset hair loss and less extensive baldness 2, 8
• Androgenetic alopecia is progressive—spontaneous improvement is rare, unlike alopecia areata where 80% of limited cases remit spontaneously 1

Counseling is Essential:

• Explain that androgenetic alopecia is a chronic progressive condition requiring lifelong treatment 10
• Discuss that initial response takes 12-24 months, so patience is necessary 10
• Address the psychological impact, as this affects quality of life significantly 9, 6