51 yo M patient is seen in the clinic for the 3 month duration of itching, and some drainage and loss of hair. Patient had used Bactrim 1 month back for skin infection, which transiently helped with the scalp lesion as well. What are the DDx and how to approach this case. 

  • Alopecia (Hair Loss)
    • Scarring Alopecia (Permanent Hair Loss)
      • Traction Alopecia
      • Central Centrifugal Cicatricial Alopecia (CCCA)
      • Lichen Planopilaris 
      • Lupus 
    • Non-Scarring Alopecia (Reversible Hair Loss) 
      • Metabolic Imbalance and Medications
        • Etiology
          • Women with PCOS, 
          • Thyroid Diseases
          • Iron Deficiency 
          • Medication Side Effects (BB, Anti-convulsants, Oral retinoids, Warfarin)
        • Often diffuse hair loss, difficult to distinguish from Telogen Effluvium
      • Androgenetic Alopecia
        • Male Pattern Alopecia
        • Female Pattern Alopecia 
        • Treatment
          • Topical Minoxidil 
          • Oral Finasteride
          • Hair Transplantation 
      • Alopecia Areata: Alopecia Totalis (Whole scalp); Alopecia Universalis (Whole Body) 
        • Autoimmune condition that targets melanocytes at the base of the hair follicles. Hence, hair that regrows first are white. 
        • Well demarcated areas of hair loss 
        • Often circular and oval, may coalesce
        • Absence of scales, or erythema 
        • Tapered "exclamation point" at the periphery 
        • Treatment: Intralesional Triamcinolone injection (5-10 mg / mL) 
      • Telogen (Final phase of hair development) Effuvium 
        • Caused by systemic stressful event (childbirth, surgery, serious illness)
        • Usually Diffuse Hair loss that occurs 3-5 month after the inciting event  
    • Reference: 
      • MKSAP 16
Further Discussion
  • Most likely DDx is Scarring Alopecia 
    • Note: Scalp Biopsy can help distinguish between scarring vs non-scarring alopecia 
  • DDX
    • CCCA, 
    • Tinea Capitis (with superimposed bacterial infection) 
      • Trichophyton tonsurans (US)
      • Microsporum canid (worldwide).