What is the best treatment approach for an adult or adolescent patient with diffuse hair loss and scalp symptoms?

Treatment Approach for Diffuse Hair Loss with Scalp Symptoms

For an adult or adolescent with diffuse hair loss and scalp symptoms, perform dermoscopy first to differentiate between diffuse alopecia areata, telogen effluvium, and androgenetic alopecia, then obtain targeted laboratory testing including TSH, serum ferritin, vitamin D, and zinc levels, followed by condition-specific treatment based on the underlying diagnosis. 1

Initial Diagnostic Evaluation

Dermoscopy as First-Line Tool

• Dermoscopy is the single most useful non-invasive tool to differentiate diffuse alopecia areata, telogen effluvium, and androgenetic alopecia. 1
• Look specifically for yellow dots, exclamation mark hairs, and cadaverized hairs—these findings are pathognomonic for alopecia areata. 1
• The absence of yellow dots and exclamation mark hairs is characteristic of telogen effluvium and androgenetic alopecia. 1
• Black dots and a positive pull test at margins signal active disease in diffuse alopecia areata. 1

Clinical History Assessment

• Assess the time course and completeness of hair loss, presence of scalp symptoms (inflammation, scaling, pruritus), signs of infection, ease of hair pull-out, and associated nail changes. 2
• Identify potential triggers: physiologic stress (illness, surgery, childbirth), emotional stress, rapid weight loss, medications (chemotherapy, anticoagulants, beta-blockers), or nutritional deficiencies. 1, 3
• Check for personal or family history of autoimmune disease, as approximately 20% of alopecia areata patients have a family history. 1
• Nail changes (pitting, ridging, dystrophy) occur in approximately 10% of alopecia areata patients. 1

Laboratory Testing Algorithm

Essential Initial Tests

• TSH to rule out thyroid disease, which is a common cause of diffuse hair loss. 1, 2
• Serum ferritin to assess for iron deficiency, the most common nutritional deficiency worldwide and a sign of chronic diffuse telogen hair loss. 1, 2
• Vitamin D levels, as 70% of alopecia areata patients have deficiency (<20 ng/mL) versus 25% of controls, with lower levels correlating inversely with disease severity. 1, 2
• Zinc levels, as serum zinc tends to be lower in alopecia areata patients, particularly those with resistant disease >6 months duration. 1, 2

Additional Tests When Indicated

• Fungal culture is mandatory when tinea capitis is suspected (scalp inflammation, scaling, erythema), as this is the most common cause of treatment failure when diagnosis is made on clinical grounds alone. 1, 2, 4
• Serology for lupus erythematosus when systemic lupus is in the differential diagnosis. 1, 2
• Serology for syphilis when secondary syphilis is suspected (patchy "moth-eaten" hair loss). 1, 2
• Scalp biopsy should be performed if dermoscopy is inconclusive and diagnosis remains uncertain after targeted laboratory testing. 1, 2

Treatment Based on Diagnosis

Diffuse Alopecia Areata

• Intralesional corticosteroid injections (triamcinolone acetonide 5-10 mg/mL) are first-line treatment for limited patchy disease with the strongest evidence (Strength B, Quality III). 1, 5
• Oral prednisolone (starting at 40 mg daily with 6-week tapering course) may show >25% regrowth in 30-47% of patients with diffuse alopecia areata. 5
• Contact immunotherapy is the best-documented treatment for extensive patchy disease, though response rates are lower in severe cases. 1
• Supplement vitamin D deficiency (<20 ng/mL) according to general international recommendations for adults, with maintenance therapy due to chronicity. 1, 5
• Zinc supplementation may contribute to hair health when deficient, particularly in patients with alopecia areata. 1, 5

Telogen Effluvium

• Spontaneous remission occurs in up to 80% of cases with short duration (<1 year) once the precipitating cause is removed. 5, 6
• Identify and address the underlying trigger (stress, illness, nutritional deficiency, medication). 1, 3
• Nutritional supplementation with vitamin D, zinc, and folate may be beneficial if deficiencies are identified. 5
• Patient education about the self-limited nature and expected timeline for regrowth is essential. 7, 3

Tinea Capitis (If Fungal Culture Positive)

• Oral antifungal therapy is required, as topical treatments are insufficient. 1, 6
• Fungal culture must be obtained before initiating treatment. 2

Androgenetic Alopecia (If Pattern Identified)

• Topical minoxidil is first-line treatment for both male and female patients. 7, 6, 8
• Oral finasteride is available as an additional treatment option for male patients. 7

Critical Pitfalls to Avoid

• Do not order excessive laboratory tests when the diagnosis is clinically evident on dermoscopy. 1
• Do not overlook dermoscopy as a non-invasive diagnostic tool that can provide valuable information and guide biopsy site selection. 1, 2
• Do not fail to consider the psychological impact of hair loss, which may cause considerable psychological and social disability warranting assessment for anxiety and depression. 1, 7
• Remember that 34-50% of alopecia areata patients recover within one year without treatment, making observation a reasonable option for limited disease. 1
• Do not assume tinea capitis only presents with patchy loss—it can masquerade as diffuse hair loss, particularly in adults. 4
• Address the psychological impact of hair loss as part of management, as patients with moderate to severe hair loss are more likely to have accompanying anxiety, depression, and lower quality-of-life scores. 5, 7