What is the appropriate treatment for a 21‑year‑old woman presenting with hair loss?

Treatment of Hair Loss in a 21-Year-Old Woman

The treatment depends entirely on the specific diagnosis, but for a young woman presenting with hair loss, you must first distinguish between the three most common patterns: patchy loss (alopecia areata), diffuse thinning with preserved frontal hairline (androgenetic alopecia), or diffuse shedding (telogen effluvium).

Diagnostic Approach

Clinical Examination Findings

• Patchy hair loss with exclamation mark hairs (short broken hairs at patch margins visible on dermoscopy) confirms alopecia areata 1, 2
• Diffuse thinning over the central scalp with intact frontal hairline indicates androgenetic alopecia (female pattern hair loss) 2, 3
• Diffuse shedding across the entire scalp suggests telogen effluvium, often triggered by stress, nutritional deficiency, or recent illness 1, 4
• Scalp inflammation or scaling points toward tinea capitis or scarring alopecia and requires fungal culture or biopsy 1, 2

Laboratory Testing Strategy

• No routine testing is needed if alopecia areata is clinically obvious with characteristic patchy loss and exclamation mark hairs 1, 2
• For diffuse hair loss patterns, check: serum ferritin (target ≥60 ng/mL for optimal hair growth), TSH, free T4, and complete blood count 2, 5
• Iron deficiency accounts for 70% of female alopecia cases, and the corresponding hemoglobin for adequate hair growth is ≥13.0 g/dL 5
• Only check testosterone, free testosterone, and SHBG if signs of androgen excess are present (acne, hirsutism, irregular periods) 2
• Avoid ordering extensive autoimmune panels in straightforward cases—this is unnecessary and wasteful 2

Treatment by Diagnosis

Alopecia Areata (Patchy Hair Loss)

For limited patchy alopecia areata of short duration (<1 year), watchful waiting with reassurance is the recommended first approach, as 34-50% of patients recover spontaneously within one year without any treatment 1, 2.

• Counsel patients that regrowth cannot be expected within 3 months of any individual patch developing 1
• No treatment has been shown to alter the long-term course of alopecia areata, though some can induce temporary hair regrowth 1

If treatment is desired for limited patches:

• Intralesional triamcinolone acetonide 5-10 mg/mL injected into affected areas is the treatment of choice 2
• Very potent topical corticosteroids (clobetasol propionate 0.05% foam) have limited evidence but may be tried 1

For extensive alopecia areata:

• Contact immunotherapy is the best-documented treatment but has less than 50% response rate and requires multiple hospital visits over months 2
• Wigs provide immediate cosmetic benefit and may be the most practical option for extensive, longstanding disease 1, 2
• Avoid systemic corticosteroids or PUVA due to serious side effects and inadequate efficacy evidence 2

Critical caveat: The psychological impact can be profound—some patients require referral to psychology for support, particularly if withdrawn, experiencing low self-esteem, or having work/social difficulties 1

Androgenetic Alopecia (Female Pattern Hair Loss)

Topical minoxidil 2% solution applied twice daily is the first-line treatment for androgenetic alopecia in women, as it arrests progression rather than stimulates regrowth 2, 3.

• Apply 1 mL twice daily directly to the scalp in the hair loss area 6
• Allow 4 hours before washing hair after application 6
• Results may take 2-4 months to appear, and treatment must be continuous—stopping will result in resumed hair loss 2, 6
• Minoxidil 5% solution may be used for potentially greater efficacy, though the 2% concentration is FDA-approved for women 6, 3

Second-line options:

• Anti-androgens (spironolactone, cyproterone acetate) are reserved for women with clinical or biochemical evidence of hyperandrogenism 7
• Platelet-rich plasma (PRP) injections show promise with a protocol of 3-5 sessions at 1-month intervals, then maintenance every 6 months 2

Important warning: Finasteride is NOT recommended for premenopausal women due to teratogenic risk 7

Telogen Effluvium (Diffuse Shedding)

Treatment focuses on identifying and correcting the underlying trigger—most cases are self-limited once the cause is addressed 4.

• Iron deficiency is the most common correctable cause: supplement iron if ferritin <60 ng/mL, aiming for ferritin ≥60 ng/mL and hemoglobin ≥13.0 g/dL 2, 5
• Initiate iron supplementation within 6 months of onset for better prognosis 5
• Address thyroid dysfunction, nutritional deficiencies (zinc, vitamin D, B12), or recent stressors 2, 4
• Reassure patients that regrowth typically occurs 3-6 months after correcting the underlying cause 4

Common Pitfalls to Avoid

• Don't confuse trichotillomania with alopecia areata: in trichotillomania, broken hairs remain firmly anchored in anagen phase, whereas alopecia areata shows exclamation mark hairs 1, 2
• Don't use more than the recommended dose of minoxidil: using more than twice daily does not speed results and may increase side effects 6
• Don't order extensive autoimmune panels for straightforward alopecia areata—the increased frequency of autoimmune disease is insufficient to justify routine screening 1, 2
• Don't promise rapid results: medical treatment arrests progression more effectively than it stimulates regrowth, and patience is essential 2, 3
• Don't overlook the psychological impact: hair loss significantly affects quality of life, and addressing emotional distress is as important as treating the physical condition 1, 4