What is the initial workup for a patient presenting with hair loss?

Initial Workup for Hair Loss

The initial workup for hair loss should include a thorough medical history, detailed scalp examination, pattern assessment, and targeted laboratory testing to determine the underlying cause and guide appropriate treatment. 1

Medical History Assessment

• Duration and progression of hair loss:

  • Acute vs. chronic onset
  • Rate of progression
  • Previous episodes and response to treatments

• Family history:

  • Pattern of hair loss in relatives (particularly important for androgenetic alopecia)

• Medical factors:

  • Recent illnesses or surgeries
  • Hormonal changes (pregnancy, menopause, thyroid disorders)
  • Autoimmune conditions
  • Nutritional status
  • Psychological stressors

• Medication review:

  • Current and recent medications that may cause hair loss (chemotherapy, anticoagulants, retinoids, antithyroid drugs, beta-blockers, antidepressants)

• Hair care practices:

  • Styling methods (tight hairstyles, heat styling)
  • Chemical treatments (perming, coloring)
  • Hair products used

Physical Examination

• Scalp assessment:

  • Presence of inflammation or scaling
  • Signs of scarring
  • Follicular prominence or loss
  • Erythema or other skin changes 1

• Hair examination:

  • Hair shaft abnormalities
  • Exclamation mark hairs (seen in alopecia areata)
  • Broken hairs (may indicate trichotillomania)
  • Hair pull test (positive when >10% of pulled hairs come out easily) 2

• Pattern assessment:

  • Diffuse thinning (telogen effluvium, anagen effluvium)
  • Patterned loss (androgenetic alopecia)
  • Patchy loss (alopecia areata, tinea capitis)
  • Scarring alopecia (lichen planopilaris, discoid lupus) 1, 3

Diagnostic Tools

• Dermoscopy (trichoscopy):

  • Essential for all hair diseases
  • Can identify yellow dots (alopecia areata)
  • Miniaturized hairs (androgenetic alopecia)
  • Black dots (broken hairs)
  • Perifollicular scaling (scarring alopecia) 4

• Laboratory testing (based on clinical suspicion):

  • Complete blood count
  • Ferritin and iron studies (levels below 70 μg/dL may require supplementation)
  • Thyroid function tests (TSH, free T4)
  • Vitamin D levels (aim for at least 30 ng/mL)
  • Zinc levels
  • Hormonal panel (testosterone, DHEAS, androstenedione) if androgenic alopecia is suspected
  • Antinuclear antibody test if autoimmune disease is suspected 1, 5

• Scalp biopsy:

  • Strongly recommended for scarring alopecia
  • Indicated in diagnostically challenging cases
  • Horizontal and vertical sections provide complementary information 4

Diagnostic Algorithm

1. Determine if scarring or non-scarring alopecia:

   • Scarring alopecia: loss of follicular ostia, skin atrophy, or scarring → refer to dermatologist
   • Non-scarring alopecia: proceed with further evaluation

2. For non-scarring alopecia, assess pattern:

   • Diffuse thinning → consider telogen effluvium, anagen effluvium, or diffuse androgenetic alopecia
   • Male or female pattern → consider androgenetic alopecia
   • Patchy loss → consider alopecia areata, tinea capitis, or trichotillomania
   • Focal loss with broken hairs → consider trichotillomania or traction alopecia

3. Order targeted laboratory tests based on clinical suspicion:

   • Diffuse loss → CBC, ferritin, thyroid function, vitamin D
   • Female pattern with signs of hyperandrogenism → hormonal panel
   • Patchy loss with scaling → fungal culture or KOH preparation

Common Pitfalls and Caveats

• Delayed diagnosis: Hair loss often progresses while patients delay seeking care due to embarrassment or assuming it's normal aging.

• Incomplete evaluation: Focusing only on the most common cause (androgenetic alopecia) may lead to missing underlying systemic diseases.

• Overlooking psychological impact: Hair loss significantly affects quality of life and may cause anxiety and depression that requires addressing 3.

• Unrealistic expectations: Patients should understand that treatment outcomes vary, and complete hair regrowth may not always be possible.

• Insufficient follow-up: Hair regrowth takes time; evaluation of treatment efficacy should occur at 3,6, and 12 months with standardized photos 1.

• Misdiagnosis of scarring vs. non-scarring alopecia: This critical distinction determines treatment approach and prognosis.