What is the appropriate initial evaluation and management for a 23‑year‑old woman presenting with fatigue and diffuse hair loss?

Initial Evaluation and Management of a 23-Year-Old Woman with Fatigue and Hair Loss

Begin with targeted laboratory testing including serum ferritin (target ≥60 ng/mL), TSH with free T4, vitamin D level, serum zinc, and complete blood count, as these nutritional and endocrine deficiencies are the most common treatable causes of diffuse hair loss in young women. 1

Clinical Assessment

History and Physical Examination

Pattern of hair loss:

• Diffuse thinning over the central scalp with preserved frontal hairline suggests androgenetic alopecia 2
• Discrete round patches with "exclamation-mark" hairs (short broken hairs at margins) are pathognomonic for alopecia areata 1, 3
• Sudden, generalized shedding 2-3 months after a triggering event (illness, stress, rapid weight loss) indicates telogen effluvium 4, 5

Dermoscopy findings:

• Yellow dots and exclamation-mark hairs confirm alopecia areata 1, 3
• Scalp inflammation or scaling suggests tinea capitis requiring fungal culture 1, 2

Associated symptoms to assess:

• Signs of androgen excess: acne, hirsutism, irregular menstrual periods (suggests PCOS) 1
• Thyroid symptoms: cold intolerance, weight changes, constipation 1
• Psychological stressors: recent major life events, emotional distress 6
• Medication history: chemotherapy, anticoagulants, beta-blockers 2

Laboratory Testing Algorithm

First-line testing for diffuse hair loss without obvious patchy alopecia: 1

• Serum ferritin (iron deficiency is the most common nutritional deficiency worldwide associated with hair loss) 1
• TSH and free T4 (thyroid disease commonly causes diffuse hair loss) 1, 2
• Vitamin D level (70% of alopecia areata patients are deficient versus 25% of controls, with lower levels correlating inversely with disease severity) 1, 3
• Serum zinc level (tends to be lower in alopecia areata patients) 1, 3
• Complete blood count (to assess for anemia) 1

Additional testing only if clinically indicated:

• Total or free testosterone and SHBG only if signs of androgen excess are present (acne, hirsutism, irregular periods) 1, 2
• Fungal culture only if scalp inflammation or scaling suggests tinea capitis 1, 2
• Scalp biopsy only when diagnosis remains uncertain after clinical and dermoscopic evaluation 1, 2

Do NOT order extensive autoimmune panels for straightforward cases, as the modest increase in autoimmune disease prevalence does not justify routine screening. 3, 2

Management Based on Diagnosis

Telogen Effluvium (Most Common in This Age Group)

Telogen effluvium accounts for the majority of diffuse hair loss cases in young women and is often triggered by psychological stress or iron deficiency. 4, 5

• Address and eliminate the underlying trigger 1
• Iron supplementation if ferritin <60 ng/mL, with reassessment at 3 months 1
• Vitamin D supplementation if levels <20 ng/mL 1, 3
• Zinc supplementation when deficient 1
• Reassure that telogen effluvium is self-limited and resolves in 3-6 months once the trigger is removed 4
• Up to 80% of cases with duration <1 year resolve spontaneously with trigger removal 2

Alopecia Areata (If Patchy Loss Present)

For limited patchy disease (≤5 patches, each ≤3 cm), watchful waiting with reassurance is legitimate first-line management, as 34-50% recover within one year without treatment. 1, 3, 2

• Counsel that visible regrowth is unlikely within the first 3 months after a new patch appears 2
• If treatment is desired, intralesional triamcinolone acetonide 5-10 mg/mL is first-line with strongest evidence (Strength B, Quality III) 1, 3
• For extensive disease (>50% scalp involvement), contact immunotherapy is best-documented but achieves response in <50% of cases 1, 2
• Wigs provide immediate cosmetic benefit for extensive disease 1, 2

Androgenetic Alopecia (If Central Thinning Pattern)

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

• Treatment must be continuous; stopping results in resumed hair loss 2
• Consider hormonal workup if signs of androgen excess are present 1

Addressing Fatigue

Assess for treatable contributing factors as recommended by cancer survivorship guidelines, which apply broadly to fatigue evaluation: 6

• Anemia (check hemoglobin and ferritin) 6, 1
• Thyroid dysfunction (TSH and free T4) 6, 1
• Emotional distress and depression (particularly important in young patients with low socioeconomic status) 6
• Sleep disturbance 6
• Nutritional deficiencies (iron, vitamin D, zinc) 1

Fatigue commonly clusters with sleep disturbance, emotional distress, or pain, and these should be specifically assessed and treated. 6

Critical Pitfalls to Avoid

• Failing to assess the psychological impact: Hair loss can cause considerable psychological and social disability in young women, warranting assessment for anxiety and depression 1, 3, 2
• Over-testing clinically evident cases: Alopecia areata is typically diagnosed clinically; extensive autoimmune panels are unnecessary 1, 3, 2
• Inadequate iron supplementation: Target ferritin ≥60 ng/mL for optimal hair growth, not just "normal range" 1, 2
• Missing the self-limited nature of telogen effluvium: Many cases resolve spontaneously with trigger removal, making watchful waiting appropriate 1, 4
• Overlooking dermoscopy: This non-invasive tool provides valuable diagnostic information (yellow dots, exclamation-mark hairs) 1, 3
• Confusing trichotillomania with alopecia areata: Trichotillomania shows firmly anchored broken hairs in anagen phase, whereas alopecia areata exhibits exclamation-mark hairs 1, 3, 2

Follow-Up

• Reassess laboratory values at 3 months after initiating supplementation 1
• Counsel that no treatment alters the long-term natural history of alopecia areata, though some can induce temporary regrowth 1, 2
• Refer to dermatology if diagnosis remains uncertain, extensive alopecia areata requires contact immunotherapy, or scarring alopecia is suspected 2