What treatment options are available for a patient with androgenetic alopecia or alopecia areata, considering potential underlying medical conditions such as thyroid disorders or autoimmune diseases?

Hair Loss Management

For androgenetic alopecia, start with topical minoxidil 5% twice daily as first-line therapy, adding oral finasteride for men if inadequate response; for alopecia areata with limited patchy disease, use intralesional triamcinolone acetonide injections, while extensive disease requires contact immunotherapy or observation given high spontaneous remission rates. 1, 2, 3

Initial Diagnostic Approach

Distinguish the Pattern Clinically

• Androgenetic alopecia presents with diffuse thinning at the crown with frontal hairline preservation in a characteristic pattern, typically genetic with family history 2
• Alopecia areata shows round or oval patches of complete hair loss with exclamation mark hairs (short broken hairs with tapered ends) around expanding patches, yellow dots on dermoscopy, and approximately 10% have nail pitting or ridging 2, 4
• Perform dermoscopy immediately—this is the single most useful non-invasive diagnostic tool, looking specifically for yellow dots and exclamation mark hairs in alopecia areata versus miniaturized hairs in androgenetic alopecia 2

Screen for Underlying Conditions

• Check thyroid stimulating hormone (TSH) to rule out thyroid disease, which commonly causes hair loss 2
• Measure serum ferritin, as iron deficiency is the most common nutritional deficiency worldwide causing chronic diffuse telogen hair loss 2
• Test vitamin D levels—70% of alopecia areata patients have deficiency (<20 ng/mL) versus 25% of controls, with lower levels correlating inversely with disease severity 2
• Consider serum zinc levels, particularly in alopecia areata patients with resistant disease >6 months duration 2
• In women with signs of androgen excess (acne, hirsutism, irregular periods), check total testosterone, free testosterone, and sex hormone binding globulin to evaluate for polycystic ovary syndrome 2

Common pitfall: Do not order excessive laboratory tests when alopecia areata diagnosis is clinically evident—investigations are unnecessary in most cases 1, 2

Treatment Algorithm for Androgenetic Alopecia

First-Line Therapy

• Topical minoxidil 5% twice daily applied directly to the scalp is the primary treatment for men, with results expected at 2-4 months 3, 5
• Minoxidil 5% reactivates hair follicles and provides more hair regrowth than 2% formulation 3
• Women should not use minoxidil 5% as studies show it works no better than 2% formulation in women, and may cause facial hair growth 3

Second-Line for Men

• Oral finasteride is available as an additional treatment option for male patients with androgenetic alopecia 5, 6
• This targets the heightened sensitivity of scalp follicles to dihydrotestosterone (DHT), the underlying mechanism 7

Expected Outcomes and Counseling

• Hair regrowth takes time—normal hair grows only 1/2 to 1 inch per month 3
• Initial hair loss may increase temporarily for up to 2 weeks when starting minoxidil, representing shedding of old hairs to regrow new ones 3
• Not everyone responds to treatment, and it is unlikely anyone will grow back all their hair 3
• Treatment must continue indefinitely to maintain results 3

Treatment Algorithm for Alopecia Areata

Limited Patchy Disease (<5 patches, <3 cm diameter)

• Reassurance alone is legitimate first approach for limited patchy hair loss of short duration, as spontaneous remission occurs in 34-50% within one year and up to 80% with limited scalp involvement 1, 4
• Intralesional triamcinolone acetonide injections achieve 62% full regrowth rates in patients with fewer than five patches less than 3 cm diameter (Strength of recommendation B, Quality of evidence III) 1, 4
• Repeat monthly injections until satisfactory response is obtained 4
• Topical minoxidil 5% can be added as adjunctive therapy, but should not be used as monotherapy 4

Extensive Patchy Disease

• Contact immunotherapy is the best-documented treatment for extensive patchy alopecia areata, though it stimulates cosmetically worthwhile hair regrowth in <50% of patients and requires multiple hospital visits over several months 1
• Potent topical corticosteroids (clobetasol propionate 0.05% foam or cream twice daily) are widely prescribed but have limited evidence—one trial showed ≥50% hair regrowth in only 21% versus 3% with placebo at 12 weeks 4
• Folliculitis is the most common side effect of potent topical steroids 4

Alopecia Totalis/Universalis

• Contact immunotherapy is the only treatment likely to be effective, though response rates are even lower than extensive patchy disease 1
• The prognosis in long-standing extensive alopecia is usually poor with high failure rates for all treatments 4
• Wigs are the most effective solution for many patients with extensive disease—acrylic wigs are cheaper and easier to maintain, while bespoke real hair wigs allow wider range of activities 1

Critical caveat: No treatment has been shown to alter the long-term course of alopecia areata; all interventions only induce temporary hair growth with high relapse rates 1, 4

Poor Prognostic Indicators

• Childhood onset carries poorer prognosis 2
• Ophiasis pattern (scalp margin involvement) has worse outcomes 2
• Disease severity at presentation is the strongest predictor—only 68% of patients with <25% hair loss initially are disease-free at follow-up 4
• Duration >6 months indicates more resistant disease 2

Nutritional Supplementation

• Supplement vitamin D deficiency (<20 ng/mL) according to general international recommendations for adults, with maintenance therapy due to chronicity 2, 4
• Zinc supplementation may contribute to hair health when deficient, particularly in alopecia areata and telogen effluvium patients 2
• No double-blind trials have yet examined oral vitamin D supplementation as a treatment strategy for alopecia areata specifically 2

Treatments to Avoid

• Continuous or pulsed systemic corticosteroids and PUVA have potentially serious side-effects with inadequate evidence of efficacy and cannot be recommended 1
• Oral zinc and isoprinosine were ineffective in controlled trials 1
• Topical corticosteroids alone have very limited evidence—one randomized trial of 0.25% desoximetasone cream failed to show significant benefit over placebo 4

Psychosocial Considerations

• Address the psychological impact directly, as alopecia areata may cause considerable psychological and social disability warranting assessment for anxiety and depression 1, 2
• Patients may feel self-conscious, conspicuous, angry, rejected, or embarrassed 4
• Patients with moderate to severe hair loss are more likely to have accompanying anxiety, depression, and lower work productivity and quality-of-life scores 5
• Educating patients about expected hair changes, treatment options, and realistic outcomes helps patients feel heard and taken seriously 5

When to Refer

• Diffuse alopecia areata that is diagnostically challenging may require scalp biopsy for histopathologic confirmation 2
• Scarring alopecia is best evaluated by a dermatologist 6
• Consider dermatology referral for contact immunotherapy in extensive disease, as this treatment is not widely available 1