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Growth Cycle of the Hair FollicleSelected Diseases of the Scalp

History and Examination
  • A thorough history is important in making the appropriate diagnosis.
Table 1.1
Hair loss history questionnaire
What is the duration and pattern of the hair loss?
Is the hair coming out by the roots, or is it breaking?
Increased shedding or increasing thinning?
Age of onset
Menses, pregnancy, menopause
Present and past health
Thyroid function screening questions
Family history
Hair care, hair cosmetics

Table 1.2
Differential diagnosis
Hair coming out by roots Hair breaking
  • Telogen effluvium
  • Androgenetic alopecia
  • Alopecia areata

  • Drugs (anagen or telogen effluvium)
  • Tinea capitis
  • Structural hair shaft abnormalities
  • Breakage due to improper use of haircare cosmetics
  • Anagen arrest
  • Clinical examination involves inspection for inflammation, scale, and erythema.  It is important to determine if the hair loss is associated with scalp scarring.
Table 1.3
Causes of alopecia
  • Androgenetic alopecia
  • Telogen effluvium
  • Alopecia areata

  • Traction alopecia
  • Tinea capitis
  • Discoid lupus erythematosus
  • Lichen planopilaris
  • Severe fungal, viral or bacterial infection
  • Injury or burn



 Pull Test
Pull Test

Scalp Biopsy
Scalp Biopsy

  • A hair pull test is very helpful to determine if hair loss is active. Approximately 60 hairs are grasped between the thumb, index and middle fingers from the base of the hairs near the scalp and firmly tugged away from the scalp. If > 6 are pulled, then this is a positive pull test.
  • Scalp biopsy may be necessary to make diagnosis.


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