### Date : 2025-07-25 17:33 ### Topic : 2.2 Diagnostic Approach to Hair Loss ---- ## 2.2 Diagnostic Approach to Hair Loss Accurate diagnosis is foundational for successful management of hair loss. A structured diagnostic approach includes clinical examination, specialized imaging, laboratory tests, and histopathological analysis. --- ### 1. Clinical Examination **Patient History:** - **Onset and progression:** sudden or gradual, acute or chronic. - **Pattern of hair loss:** diffuse, patchy, frontal, temporal, or vertex. - **Associated symptoms:** itching, burning, scaling, erythema, or systemic symptoms. - **Triggers:** recent stress, surgery, pregnancy, medications, or illness. - **Family history:** androgenetic alopecia, autoimmune conditions. - **Past medical history:** autoimmune disease, endocrinopathies, nutritional deficiencies. **Physical Examination:** - Assess scalp for inflammation, scaling, scarring, or follicular changes. - Document distribution pattern (diffuse, patchy, patterned). - Evaluate hair shaft integrity, length variation, and follicular openings. - Examine eyebrows, eyelashes, body hair for generalized involvement. --- ### 2. Trichoscopy (Scalp Dermoscopy) Trichoscopy is a non-invasive, essential tool enhancing diagnostic precision. **Technique:** - Digital or handheld dermatoscope (10x-70x magnification). - Utilize polarized or non-polarized light for clear visualization. **Key Diagnostic Signs:** - **Androgenetic alopecia:** - Hair shaft diameter variability (>20%), miniaturization - Yellow dots, peripilar signs, empty follicles - Thin, short, vellus-like hairs - **Alopecia areata:** - Exclamation mark hairs, black dots (broken hairs) - Yellow dots, vellus hairs - **Telogen effluvium:** - Uniform hair shaft diameter (no significant miniaturization) - Increased telogen hairs without perifollicular signs - **Scarring alopecias:** - Loss of follicular openings - Perifollicular erythema, scaling ("peripilar casts") - White patches indicating fibrosis --- ### 3. Scalp Biopsy (Histopathology) Performed when clinical and dermoscopic evaluation is inconclusive or for definitive diagnosis of inflammatory/scarring alopecia. **Indications:** - Suspected scarring alopecia (FFA, LPP, DLE). - Ambiguous cases of chronic telogen effluvium or androgenetic alopecia. - Suspected underlying inflammatory or neoplastic conditions. **Procedure:** - 4 mm punch biopsy (preferably two samples: vertical & horizontal sections). - Choose active edge of lesion if inflammatory alopecia is suspected. - Vertical section: evaluates epidermis, dermis, subcutaneous tissue. - Horizontal section: assesses follicular architecture and follicle count. **Histopathological Hallmarks:** - **AGA:** Miniaturized follicles, increased vellus-to-terminal hair ratio, perifollicular fibrosis. - **Alopecia Areata:** "Swarm-of-bees" lymphocytic infiltrate surrounding anagen bulbs. - **Telogen Effluvium:** Normal follicular anatomy, increased proportion of telogen hairs (>15%). - **Lichen Planopilaris/FFA:** Interface dermatitis, perifollicular fibrosis, lichenoid infiltrate. - **Discoid Lupus Erythematosus:** Basement membrane thickening, follicular plugging, dermal mucin deposition, lymphocytic infiltrate. --- ### 4. Hair Pull Test and Epiluminescence Microscopy **Hair Pull Test (Screening Test):** - Grasp approximately 50-60 hairs firmly, pull gently from multiple scalp regions. - Normal shedding: fewer than 10% hairs removed per pull. - Increased shedding (>10% telogen hairs): suggests telogen effluvium, active alopecia areata. **Epiluminescence Microscopy (Hair Root Examination):** - Examine hair roots under microscopy after pull test. - Anagen hairs: darkly pigmented, sheath-covered roots. - Telogen hairs: club-shaped, non-pigmented root bulbs. --- ### 5. Hormonal and Biochemical Tests Conducted when suspecting endocrine, metabolic, nutritional causes, or systemic disease involvement. **Recommended Tests:** - **Complete blood count (CBC)**: rule out anemia, chronic disease. - **Iron studies (Ferritin, serum iron, TIBC)**: evaluate iron deficiency, common cause of telogen effluvium. - **Vitamin D, B12 levels**: nutritional deficiencies associated with diffuse shedding. - **Thyroid-stimulating hormone (TSH), Free T4**: rule out hypothyroidism/hyperthyroidism. - **Hormonal profile (women)**: DHEA-S, testosterone, prolactin, LH/FSH for suspected androgen excess (PCOS, hyperandrogenism). - **Autoimmune markers (ANA, anti-dsDNA, ESR, CRP)**: if lupus erythematosus or other autoimmune disorders suspected. ---