One-liner#

Evaluate hair loss to distinguish common pattern hair loss and telogen effluvium from scarring alopecias requiring urgent treatment, initiating appropriate therapy while identifying underlying systemic causes.

Quick nav#

• Red flags / send to ED
• Key history
• Focused exam
• Differential (quick pattern recognition)
• Workup
• Initial management
• Management by diagnosis
• Follow-up
• Patient instructions
• Smartphrase snippets

Red flags / send to ED#

• Hair loss is rarely an emergency

Urgent (not ED, but expedited referral):

• Scarring alopecia (permanent hair loss if untreated) → derm referral within 2-4 weeks
• Rapidly progressive hair loss with scalp symptoms (pain, burning, itching)
• Hair loss with signs of systemic disease (lupus, thyroid storm)

Key history#

Pattern and distribution:

• Diffuse vs patchy vs patterned
• Scalp only vs body hair also affected
• Symmetric vs asymmetric

Timeline:

• Acute onset vs gradual
• Duration
• Progression: stable, worsening, improving
• Any recent regrowth

Associated symptoms:

• Scalp symptoms: itching, burning, pain, tenderness
• Skin changes: scaling, redness, scarring
• Systemic symptoms: fatigue, weight changes, cold/heat intolerance

Triggers (for telogen effluvium):

• Major illness, surgery, hospitalization (2-4 months prior)
• Childbirth (2-4 months postpartum)
• Significant weight loss or crash dieting
• High fever
• Emotional stress
• Starting or stopping medications (especially hormonal)

Medications causing hair loss:

• Chemotherapy (anagen effluvium)
• Anticoagulants (heparin, warfarin)
• Retinoids (isotretinoin, acitretin)
• Antithyroid medications
• Beta-blockers
• ACE inhibitors
• Lithium
• Valproic acid
• Hormonal changes (stopping OCPs)

Hair care practices:

• Tight hairstyles (braids, ponytails, extensions) → traction alopecia
• Chemical treatments (relaxers, perms, dyes)
• Heat styling
• Hair pulling (trichotillomania)

Medical history:

• Thyroid disease
• Iron deficiency/anemia
• Autoimmune disease (lupus, alopecia areata)
• PCOS
• Recent pregnancy

Family history:

• Pattern hair loss (androgenetic alopecia)
• Autoimmune disease

Focused exam#

Scalp examination:

• Distribution: diffuse, patchy, patterned (frontal/vertex)
• Scalp skin: normal, erythema, scaling, scarring, atrophy
• Follicular ostia: visible (non-scarring) vs absent (scarring)
• Hair density: compare affected to unaffected areas
• Hair caliber: miniaturized hairs (androgenetic alopecia)

Hair pull test:

• Grasp 40-60 hairs between thumb and fingers
• Gentle traction from scalp to ends
• Normal: 0-2 hairs
• Positive: >6 hairs (suggests active shedding—telogen effluvium, alopecia areata)

Key distinguishing features:

Specific findings:

• Exclamation point hairs: short, broken hairs that taper at base (alopecia areata)
• “Friar Tuck” pattern: frontal and vertex thinning with preserved sides (male pattern)
• Christmas tree pattern: widening of central part (female pattern)
• Broken hairs at different lengths: trichotillomania or tinea capitis
• Black dots: broken hairs at scalp level (tinea capitis, trichotillomania)

Differential (quick pattern recognition)#

Common/likely (outpatient) — Non-scarring#

Can’t-miss / urgent — Scarring alopecias#

Workup#

Most hair loss is diagnosed clinically. Labs for suspected systemic cause or when diagnosis unclear.

First-line labs (when indicated):

Second-line labs:

Scalp biopsy:

• For scarring alopecia (to confirm diagnosis and guide treatment)
• When diagnosis uncertain despite clinical evaluation
• Derm performs; two 4mm punch biopsies (horizontal and vertical sectioning)

KOH prep:

• Suspected tinea capitis
• Scrape scale and broken hairs

Initial management#

Key first step: Determine if scarring or non-scarring

• Scarring: urgent derm referral (permanent if untreated)
• Non-scarring: can often manage in primary care

Management by diagnosis#

Androgenetic alopecia (male pattern)#

Education:

• Genetic; affects ~50% of men by age 50
• Progressive without treatment
• Treatment slows progression and may regrow some hair
• Must continue treatment indefinitely to maintain results

Treatment:

Finasteride counseling:

• Sexual side effects (decreased libido, ED) in 2-4%; usually resolve with continued use or stopping
• Rare: depression, persistent sexual dysfunction (controversial)
• Do not donate blood while taking (teratogenic)
• PSA will decrease ~50%; adjust interpretation for prostate cancer screening

Follow-up: 6-12 months to assess response.

Androgenetic alopecia (female pattern)#

Education:

• Affects ~40% of women by age 50
• Diffuse thinning with preserved frontal hairline
• Rule out hyperandrogenism if other signs (hirsutism, acne, irregular menses)
• Treatment slows progression

Treatment:

If hyperandrogenism suspected:

• Check testosterone, DHEA-S, consider PCOS workup
• Treat underlying cause

Follow-up: 6-12 months to assess response.

Telogen effluvium#

Education:

• Diffuse shedding 2-4 months after trigger
• Common triggers: childbirth, major illness, surgery, high fever, crash diet, emotional stress, medication changes
• Self-limited; usually resolves in 6-12 months
• Hair will regrow once trigger resolved

Common triggers:

• Postpartum (very common)
• Major surgery or illness
• High fever
• Significant weight loss
• Stopping oral contraceptives
• Emotional stress
• Medications

Treatment:

• Identify and address trigger
• Reassurance (most important)
• Optimize nutrition (protein, iron, vitamin D)
• No specific treatment needed; hair regrows spontaneously

Follow-up: 3-6 months; reassess if not improving by 12 months.

Alopecia areata#

Education:

• Autoimmune condition; T-cells attack hair follicles
• Presents as smooth, round patches of hair loss
• Unpredictable course; may regrow spontaneously or progress
• Associated with other autoimmune conditions (thyroid, vitiligo)
• Not contagious

Treatment:

Limited disease (<50% scalp involvement):

Extensive disease (>50% scalp) or refractory:

• Derm referral
• Options: topical immunotherapy (DPCP), JAK inhibitors (baricitinib, ritlecitinib), systemic steroids (short-term)

Follow-up: 6-8 weeks after intralesional steroids; derm referral if extensive or not responding.

Tinea capitis#

Education:

• Fungal infection of scalp; common in children
• Requires oral antifungal (topical does not penetrate hair shaft)
• Contagious; check household contacts
• May cause kerion (boggy, inflammatory mass)

Treatment:

Adjunctive:

• Selenium sulfide 2.5% or ketoconazole 2% shampoo 2-3x/week (reduces spore shedding)
• Treat household contacts if symptomatic
• Do not share combs, brushes, hats

Kerion:

• Inflammatory response; not abscess
• Treat with oral antifungal (same as above)
• May add short course of prednisone (1 mg/kg x 1-2 weeks) to reduce inflammation
• Do NOT incise and drain

Follow-up: 4-6 weeks; continue treatment until clinical and mycologic cure.

Scarring alopecias (general approach)#

Education:

• Permanent hair loss if untreated
• Goal is to stop progression (regrowth unlikely in scarred areas)
• Requires biopsy for diagnosis
• Long-term treatment often needed

PCP role:

• Recognize scarring alopecia (absent follicular ostia, smooth scalp)
• Urgent derm referral (within 2-4 weeks)
• Do not delay for labs or empiric treatment

Treatment (derm-initiated):

• Lichen planopilaris/frontal fibrosing alopecia: topical/intralesional steroids, hydroxychloroquine, doxycycline
• Central centrifugal cicatricial alopecia: stop chemical/heat treatments, topical steroids, doxycycline
• Discoid lupus: topical steroids, hydroxychloroquine, treat systemic lupus

Follow-up#

• Androgenetic alopecia: 6-12 months to assess treatment response
• Telogen effluvium: 3-6 months; should resolve by 12 months
• Alopecia areata: 6-8 weeks after treatment
• Tinea capitis: 4-6 weeks
• Scarring alopecia: Derm manages

Return precautions:

• Rapid progression of hair loss
• New scalp symptoms (pain, burning, itching)
• Signs of scarring (smooth, shiny scalp)
• Hair loss not improving as expected
• New patches appearing

Patient instructions#

• Hair loss has many causes. We will work together to find the cause and best treatment.
• Most hair loss is not permanent and can be treated.
• Treatments take time—usually 4-6 months to see improvement. Be patient.
• If you’re using minoxidil, apply it consistently every day. Stopping will cause hair loss to resume.
• Avoid tight hairstyles, excessive heat, and harsh chemical treatments.
• Eat a balanced diet with adequate protein and iron.
• If you notice smooth, shiny patches where hair won’t grow back, call the office—this may need urgent treatment.

Smartphrase snippets#

.HAIRLOSSAGA Androgenetic alopecia ([male/female] pattern). [Distribution]. No signs of scarring alopecia. Plan: [minoxidil 5% daily / finasteride 1 mg daily]. Discussed that treatment takes 4-6 months to show results and must be continued indefinitely. [For finasteride: Discussed potential sexual side effects.] Follow-up in 6-12 months.

.HAIRLOSSTE Telogen effluvium, likely triggered by [trigger] approximately [timeframe] ago. Diffuse shedding; positive hair pull test; no scarring. Labs: [TSH, ferritin, CBC ordered / normal]. Plan: reassurance—this is self-limited and hair will regrow over 6-12 months. [Iron/vitamin D supplementation if deficient.] Follow-up in 3-6 months if not improving.

.HAIRLOSSAA Alopecia areata with [number/size] patches. Smooth, round patches without scarring. Plan: [intralesional triamcinolone / topical clobetasol / derm referral for extensive disease]. Discussed autoimmune nature and unpredictable course. Follow-up in 6-8 weeks.

.HAIRLOSSSCARRING Hair loss with features concerning for scarring alopecia: [absent follicular ostia / smooth scalp / perifollicular erythema]. Urgent dermatology referral placed for biopsy and treatment. Discussed that scarring alopecia can cause permanent hair loss if not treated promptly.