What are the treatment options for an adult patient experiencing hair loss or thinning?

Treatment for Hair Loss or Thinning

Diagnosis is Critical: Different Types Require Completely Different Treatments

The first and most important step is determining whether you have androgenetic alopecia (pattern baldness) versus alopecia areata (patchy autoimmune hair loss), as these require entirely different treatments and mixing them up will result in treatment failure. 1, 2

Key Diagnostic Features

Androgenetic Alopecia (Pattern Baldness):

• Diffuse thinning over the central scalp with preserved frontal hairline in women 3
• Temporal, vertex, or mid-frontal involvement in men with preserved occipital and lateral scalp hair 2
• Gradual onset over years 4
• Family history common 5

Alopecia Areata (Autoimmune):

• Discrete, well-demarcated patches of complete hair loss 3
• Exclamation mark hairs (short broken hairs at patch margins) - pathognomonic finding 1, 3
• No scalp inflammation or scaling 3
• 20% have family history 3

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Treatment Algorithm for Androgenetic Alopecia (Pattern Baldness)

First-Line Treatment: FDA-Approved Medications

For men, initiate combination therapy with oral finasteride 1 mg daily PLUS topical minoxidil 5% solution twice daily - these are the only FDA-approved treatments proven to halt progression and stimulate regrowth. 2, 4

For women, start with topical minoxidil 2% solution twice daily as first-line treatment, which arrests progression rather than stimulates regrowth. 3, 4

Critical counseling points:

• Treatment must be continuous indefinitely to maintain results - stopping will cause hair loss to resume 3, 6
• Results take time: may see improvement at 2 months, but some patients require 4 months before seeing results 4
• Initial increased shedding for up to 2 weeks is expected and indicates the treatment is working (shedding old hairs to regrow new ones) 4
• New hair initially appears as soft, downy, colorless "peach fuzz" before becoming normal thickness and color 4

Second-Line Treatment: Platelet-Rich Plasma (PRP) Injections

If response to minoxidil (with or without finasteride) is suboptimal after 6 months, add PRP injections as adjunctive therapy. 2, 3

Specific PRP protocol based on highest quality evidence:

• Preparation: Manual double-spin method, target platelet concentration 1-1.5 million platelets/µL, use NONactivated PRP (31% greater improvement than activated) 6
• Treatment phase: 3-5 sessions at 1-month intervals 2, 6
• Dose: 5-7 mL PRP per session, 0.05-0.1 mL/cm² 6
• Injection technique: 90-degree angle, 2-4 mm depth, injections 1 cm apart, using 30G × 4mm needles 6
• Maintenance phase: 1 session every 6 months after initial treatment 2, 6
• Pain management: Apply pharmaceutical-grade topical anesthetic cream before injection due to significant pain 6

Expected outcomes with combination therapy (minoxidil + PRP):

• 57% median increase in terminal hair density versus 48% with minoxidil alone at 32 weeks 6
• 83% achieve negative hair pull test indicating reduced hair fragility 6
• Maximum response typically achieved by 6 months 6

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Treatment Algorithm for Alopecia Areata (Patchy Autoimmune Hair Loss)

Limited Patchy Disease (Few Small Patches)

Watchful waiting with reassurance is a legitimate first option, as 34-50% of patients with limited patchy hair loss of short duration (<1 year) recover spontaneously within one year without treatment. 1, 3

Counsel patients that:

• Regrowth cannot be expected within 3 months of any individual patch development 1
• No treatment alters the long-term course of alopecia areata, though some can induce temporary regrowth 1, 3

If treatment is desired for limited disease:

• Intralesional corticosteroids (triamcinolone acetonide 5-10 mg/mL) injected just beneath the dermis - Strength of Recommendation B 1, 3
• 0.05-0.1 mL injection produces tuft of hair growth about 0.5 cm in diameter 1
• 62% of patients with fewer than 5 patches <3 cm achieved full regrowth with monthly injections 1
• Skin atrophy at injection site is consistent side-effect 1

Extensive Disease (Multiple Large Patches or Total Scalp Involvement)

Contact immunotherapy (DPCP or SADBE) is the best-documented treatment for extensive alopecia areata, though it has less than 50% response rate and requires multiple hospital visits over months. 1, 3

Protocol for contact immunotherapy:

• Sensitize with 2% DPCP solution to small scalp area 1
• Two weeks later, apply 0.001% DPCP weekly, increasing concentration until mild dermatitis occurs 1
• Continue treatment at maintenance concentration 1

For extensive disease, wigs provide immediate cosmetic benefit and may be preferable to treatments with low success rates. 1, 3

Treatments to AVOID in Alopecia Areata

Do NOT use these treatments - they are ineffective or have unacceptable risk-benefit ratios:

• Potent topical corticosteroids (lack convincing evidence) 1, 3
• Systemic corticosteroids or PUVA (potentially serious side-effects, inadequate efficacy evidence) 3
• Oral zinc or isoprinosine (ineffective in controlled trials) 3
• Anti-TNF biologic drugs like etanercept (proven ineffective) 1

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Laboratory Testing: When and What to Order

Investigations are unnecessary in most cases when the diagnosis is clinically evident. 3

Order targeted laboratory tests ONLY if:

• Diagnosis is uncertain 3
• Signs of underlying systemic disease present 3

Specific tests to consider based on clinical suspicion:

• Serum ferritin if iron deficiency suspected (optimal ≥60 ng/mL needed for hair growth) 3
• TSH and free T4 if thyroid disease suspected 3
• Fungal culture only if tinea capitis suspected (scalp inflammation/scaling present) 3
• Skin biopsy reserved for uncertain diagnosis or suspected scarring alopecia 3
• Total testosterone, free testosterone, SHBG only if signs of androgen excess (acne, hirsutism, irregular periods) 3

Common pitfall: Ordering extensive autoimmune panels in straightforward alopecia areata cases is unnecessary and not cost-effective 3

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Monitoring Treatment Response

Use multiple objective measures to track progress:

• Standardized before-and-after photographs 2, 6
• Trichoscopy to evaluate hair density and diameter 6
• Hair pull test to evaluate hair fragility 6
• Patient self-assessment questionnaires 2, 6

Key indicators of positive response:

• Increased hair density 6
• Increased hair shaft diameter 6
• Decreased proportion of telogen hairs 6
• Improved patient satisfaction scores 6

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Critical Pitfalls to Avoid

For androgenetic alopecia:

• Delaying effective treatment with finasteride and minoxidil while trying unproven supplements may result in irreversible hair loss 2
• Low platelet concentration, inadequate injection volume, or insufficient treatment frequency leads to PRP treatment failure 6
• Insufficient treatment duration - some patients require extended therapy beyond initial 6 months 6

For alopecia areata:

• Using potent topical corticosteroids (indicated only for alopecia areata, NOT androgenetic alopecia) 2
• Failing to consider trichotillomania where broken hairs remain firmly anchored 3
• Pursuing aggressive treatment in extensive long-standing disease where prognosis is poor and wigs may be better option 1