What is the recommended workup and first‑line management for adult hair loss (alopecia)?

Workup and Management of Adult Hair Loss

For adult hair loss, the recommended approach begins with clinical pattern recognition to distinguish alopecia areata (patchy loss with exclamation-mark hairs) from androgenetic alopecia (diffuse central thinning with preserved frontal hairline) or telogen effluvium (diffuse shedding), as laboratory testing is unnecessary when the diagnosis is clinically evident. 1, 2

Initial Clinical Assessment

Pattern recognition is the cornerstone of diagnosis:

• Patchy hair loss with exclamation-mark hairs (short broken hairs at patch margins) confirms alopecia areata and can be identified with dermoscopy 1, 2
• Diffuse central scalp thinning with preserved frontal hairline indicates androgenetic alopecia 2, 3
• Diffuse shedding across the entire scalp suggests telogen effluvium, often precipitated by stress, nutritional deficiency, or recent illness 2, 4
• Scalp inflammation or scaling raises concern for tinea capitis or scarring alopecia and warrants fungal culture or biopsy 2, 5

Key history elements include:

• Duration of hair loss: onset <1 year predicts better prognosis with 34-50% spontaneous remission in limited alopecia areata 1, 2
• Family history: present in 20% of alopecia areata cases 2
• Medication history: chemotherapy causes anagen effluvium 2
• Hair-care practices: tight hairstyles suggest traction alopecia 2

Laboratory Testing Strategy

The British Association of Dermatologists emphasizes that investigations are unnecessary in most cases when the diagnosis is clinically evident. 1, 2

Targeted testing only when diagnosis is uncertain or systemic disease is suspected:

• Fungal culture: only if scalp inflammation or scaling suggests tinea capitis 1, 2
• Skin biopsy: reserved for uncertain diagnosis or suspected scarring alopecia 1, 2
• Serum ferritin: if iron deficiency suspected (optimal ≥60 ng/mL needed for hair growth) 2
• TSH and free T4: if thyroid disease suspected 2
• Total testosterone, free testosterone, SHBG: only if signs of androgen excess (acne, hirsutism, irregular periods) 2

Common pitfall: Ordering extensive autoimmune panels in straightforward alopecia areata is unnecessary, as the modest increase in autoimmune disease prevalence does not justify routine screening 1, 2

First-Line Management by Diagnosis

Limited Patchy Alopecia Areata (≤5 patches, each ≤3 cm)

Watchful waiting with reassurance is the legitimate first-line approach, as 34-50% of patients recover within one year without treatment. 1, 2

• Counsel patients that regrowth cannot be expected within 3 months of any individual patch 1, 2
• No treatment alters the long-term course of alopecia areata, though some induce temporary regrowth 1, 2

If treatment is desired:

• Intralesional triamcinolone acetonide 5-10 mg/mL (0.05-0.1 mL per injection, administered monthly) yields regrowth in approximately 62% of patients, with effects lasting about 9 months (Strength of recommendation B, Quality III) 1, 2
• Inject just beneath the dermis in the upper subcutis; each 0.05-0.1 mL injection produces a tuft of hair growth about 0.5 cm in diameter 1
• Main limitation is patient discomfort; skin atrophy at injection sites is a consistent side-effect 1

Treatments to avoid:

• Potent topical corticosteroids lack convincing efficacy evidence 1, 2
• Dithranol and minoxidil lotion are widely prescribed but have no convincing evidence of effectiveness 1

Extensive Alopecia Areata (>50% scalp involvement, alopecia totalis/universalis)

Contact immunotherapy with diphenylcyclopropenone (DPCP) is the best-documented treatment but achieves cosmetically worthwhile regrowth in <50% of patients (Strength of recommendation C). 1, 2

• Requires multiple hospital visits over several months 1, 2
• Protocol: sensitize with 2% DPCP to small scalp area, then apply weekly starting at 0.001%, increasing concentration until mild dermatitis occurs 1
• Some temporary local inflammation but serious side-effects are rare 1

Wigs provide immediate cosmetic benefit and are often the most practical solution for extensive, longstanding disease (Strength of recommendation D). 1, 2

Treatments not recommended:

• Systemic corticosteroids and PUVA have potentially serious side-effects and inadequate efficacy evidence 1, 2
• Oral zinc and isoprinosine are ineffective in controlled trials 2

Androgenetic Alopecia

For men: Initiate combination therapy with oral finasteride 1 mg daily and topical minoxidil 5% solution twice daily, as this is the only FDA-approved approach proven to halt progression and stimulate regrowth. 2, 3

For women: Topical minoxidil 2% solution twice daily is first-line treatment, which arrests progression rather than stimulates regrowth. 2

• Treatment must be continuous to maintain results; stopping leads to resumed hair loss 2, 3
• Initial therapeutic response often takes 12-24 months 6
• Monitor response with standardized photographs 3

Adjunctive therapy:

• Platelet-rich plasma (PRP) injections show promise with increased hair density: 3-5 sessions at 1-month intervals, then maintenance every 6 months 2, 3

Telogen Effluvium

Removal of the precipitating trigger (stress, nutritional deficiency, illness) leads to spontaneous remission in up to 80% of cases with short duration (<1 year). 1, 2

Tinea Capitis

Systemic oral antifungal therapy is required; fungal culture must be obtained before initiating treatment. 2

Critical Pitfalls to Avoid

• Do not confuse trichotillomania with alopecia areata: trichotillomania shows broken hairs firmly anchored in anagen, whereas alopecia areata displays exclamation-mark hairs 1, 2
• Failing to address psychological impact: hair loss can cause considerable psychological and social disability; patients with low self-esteem or work/social difficulties should be considered for mental-health referral 1, 2
• Starting aggressive treatments in children: intralesional steroids are often poorly tolerated and many clinicians are reluctant to use contact immunotherapy in pediatric patients 1

When to Refer to Dermatology

• Diagnosis remains uncertain despite clinical and dermoscopic evaluation 2
• Extensive alopecia areata requiring contact immunotherapy 2
• Suspected scarring alopecia or treatment-resistant cases 2
• Need for scalp biopsy when diagnosis cannot be clarified by non-invasive methods 2