About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
The Bottom Line
- The most important distinction is scarring vs non-scarring alopecia; loss of follicular openings, scale, pustules, erythema, or pain suggests scarring/inflammatory disease
- Diffuse shedding after illness, childbirth, surgery, weight loss, iron deficiency, thyroid disease, or medication exposure suggests telogen effluvium
- Smooth patchy hair loss with exclamation-mark hairs suggests alopecia areata; screen for autoimmune context when clinically indicated
- Tinea capitis in children requires systemic antifungal therapy; topical treatment alone is inadequate
- Hair loss has major psychosocial impact; communication, expectation-setting, and follow-up matter in addition to diagnosis
Approach to the Presentation
Hair loss should be described by distribution, tempo, symptoms, and scalp findings. Start with scarring vs non-scarring: if follicular openings are absent, the scalp is shiny, inflamed, pustular, painful, or scaling, urgent dermatology referral is appropriate because permanent alopecia can occur. Then classify as focal/patchy, patterned, or diffuse. Ask about recent physiological stress, childbirth, febrile illness, surgery, crash dieting, new medications, endocrine symptoms, menstrual/androgen excess symptoms, autoimmune disease, hair practices, traction, compulsive pulling, and family history. Examine the scalp, hair shaft, eyebrows, body hair, nails, and skin. Pull test and dermoscopy can help, but the exam emphasis is usually recognizing common patterns and not missing tinea capitis or scarring disease.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Scarring Alopecia (lichen planopilaris, discoid lupus, frontal fibrosing alopecia, folliculitis decalvans) | must-not-miss | Loss of follicular openings, perifollicular scale/erythema, pustules, pain, burning, shiny scarred patches; permanent loss if untreated | Urgent dermatology; scalp biopsy from active margin |
| Tinea Capitis / Kerion | must-not-miss | Child with patchy alopecia, scale, broken hairs, lymphadenopathy; kerion is boggy inflammatory plaque and can scar | Fungal culture/KOH; treat systemically if suspected |
| Systemic Disease-Associated Alopecia (thyroid disease, iron deficiency, SLE, syphilis) | must-not-miss | Diffuse shedding or patchy loss with fatigue, menstrual change, weight change, rash, arthralgia, mucosal lesions, STI risk | CBC, ferritin, TSH; ANA or syphilis serology if clinically indicated |
| Chemotherapy / Anagen Effluvium | must-not-miss | Abrupt diffuse hair loss days to weeks after chemotherapy, toxins, or radiation; affects actively growing hair | Medication/treatment timeline |
| Androgenetic Alopecia | common | Patterned hair thinning: bitemporal/vertex in men; central part widening in women; family history; gradual course | Clinical diagnosis; consider androgen excess workup in women with hirsutism, acne, irregular menses |
| Telogen Effluvium | common | Diffuse shedding 2-3 months after stressor: childbirth, illness, surgery, weight loss, iron deficiency, medication; positive hair pull test | Clinical timeline; CBC/ferritin/TSH when indicated |
| Alopecia Areata | common | Smooth well-circumscribed patches, exclamation-mark hairs, nail pitting; autoimmune associations; may involve beard/eyebrows | Clinical diagnosis; dermoscopy; biopsy if atypical |
| Traction Alopecia | common | Hair loss along hairline or areas under tension from braids, extensions, tight ponytails, headwear; fringe sign may be present | Hair practice history; early disease is reversible, chronic disease can scar |
| Trichotillomania | less common | Irregular patches with hairs of varying length, broken hairs, psychiatric stressors; often frontoparietal and accessible areas | Clinical/dermoscopic findings; sensitive psychosocial history |
| Medication-Induced Hair Loss | less common | Diffuse shedding after retinoids, anticoagulants, beta-blockers, valproate, lithium, antithyroid drugs, hormonal changes | Medication timeline and dechallenge when appropriate |
Red Flags & Key History
Symptoms
Pain, burning, tenderness, pustules, scale, or rapidly progressive patches — scarring/inflammatory alopecia
Child with patchy scaling hair loss, broken hairs, lymphadenopathy, or boggy kerion
Systemic symptoms: fatigue, weight change, fever, arthralgia, photosensitivity, mucosal ulcers, STI risk
Recent chemotherapy, radiation, poisoning/toxin exposure, or severe acute illness
Severe psychological distress, social withdrawal, or self-harm thoughts related to hair loss
Hair shedding 2-3 months after childbirth, febrile illness, surgery, COVID-19-like illness, weight loss, or stress
Tight hairstyles, extensions, chemical straightening, traction, or occupational headwear
Signs
Loss of follicular ostia, shiny scarred scalp, perifollicular erythema/scale
Boggy inflammatory plaque or pustular scalp lesion
Patchy smooth alopecia with exclamation-mark hairs
Central part widening or bitemporal/vertex miniaturization
Irregular broken hairs of varying lengths
Nail pitting with alopecia patches
Approach to Investigation
First-line
Scalp examination and hair pull testAssess follicular openings, inflammation, scale, pustules, scarring, miniaturization, broken hairs, and active shedding
CBC, ferritin, TSH when diffuse shedding or systemic symptoms existScreens for anaemia/iron deficiency and thyroid disease, common reversible contributors
Fungal testing for suspected tinea capitisKOH/culture from scale and plucked hairs; do not delay systemic therapy in classic kerion
Medication, reproductive, endocrine, and hair-care reviewHigh yield for telogen effluvium, androgen excess, drug-induced alopecia, and traction alopecia
Second-line
Scalp biopsyIndicated for suspected scarring alopecia, atypical alopecia areata, unclear diffuse alopecia, or treatment-resistant disease; sample active edge
Androgen evaluationConsider total/free testosterone, DHEAS, prolactin, or PCOS workup if women have hirsutism, acne, virilization, or menstrual irregularity
Autoimmune/STI testingANA, syphilis serology, or other tests only when history/examination suggests SLE, secondary syphilis, or systemic disease
Specialist
Dermatology referralUrgent for scarring alopecia, kerion, rapidly progressive disease, diagnostic uncertainty, or need for intralesional/systemic therapy
Mental health supportFor trichotillomania, severe distress, body-image impairment, anxiety, depression, or social avoidance
Management Principles
MCC Skin and Integument Conditions objective + Canadian Dermatology Association resources1
Non-scarring patterned or diffuse alopecia
- Androgenetic alopecia: topical minoxidil; consider oral anti-androgen strategies in selected women under appropriate supervision; counsel that response takes months
- Telogen effluvium: identify and correct trigger, reassure about regrowth, optimize nutrition/iron/thyroid status when abnormal
- Medication-induced alopecia: review risk-benefit before stopping essential medications; substitute only when clinically safe
2
Patchy alopecia
- Alopecia areata: education, intralesional corticosteroids for limited adult scalp disease when available, topical therapies in selected cases, dermatology for extensive disease
- Tinea capitis: systemic antifungal therapy; treat household spread and advise against sharing combs/hats
- Trichotillomania: non-judgmental discussion, habit-reversal therapy/CBT, and mental health support
3
Scarring or inflammatory alopecia
- Urgent dermatology referral because lost follicles do not regrow
- Avoid delaying referral with prolonged empiric topical treatment if scarring signs are present
- Treat infection, inflammation, or autoimmune disease according to specialist plan
4
Counselling
- Set expectations: hair cycles are slow and visible response often takes 3-6 months
- Address cosmetic options, camouflage, wigs, workplace/school impact, and emotional burden
- Use sensitive language; hair loss is not trivial to the patient
Complications & Pitfalls
- Missing scarring alopecia: Delay can make hair loss permanent.
- Treating tinea capitis topically only: Scalp dermatophyte infection requires systemic antifungal therapy.
- Over-investigating obvious androgenetic alopecia: Labs are guided by systemic symptoms, diffuse shedding, or androgen excess features.
- Ignoring traction practices: Early traction alopecia is reversible; chronic disease can scar.
- Minimizing distress: Alopecia can severely affect identity, confidence, and mental health.
MCCQE1 Exam Tips
- 1First split alopecia into scarring vs non-scarring. Loss of follicular openings = urgent dermatology
- 2Diffuse shedding 2-3 months after a stressor = telogen effluvium; reassure and correct triggers
- 3Smooth circular patches with exclamation-mark hairs = alopecia areata
- 4Child with scale, broken hairs, lymphadenopathy, or kerion = tinea capitis; systemic antifungal therapy is required
- 5Female pattern hair loss plus hirsutism/acne/irregular menses suggests androgen excess or PCOS workup
- 6Irregular broken hairs of different lengths with accessible distribution suggests trichotillomania
- 7Hair-loss questions often test communication: validate distress and set realistic timelines for regrowth
practicetest your knowledge on hair lossApply what you've learnt with MCCQE1-style questions from the iatroX Q-Bank — dermatologic and beyond.
open q-bank