• Nonscarring alopecias
  • Androgenetic alopecia
  • Alopecia areata
  • Trichotillomania
  • Tinea capitis
  • Telogen effluvium
  • Anagen effluvium
• Scarring (Cicatricial) alopecia
  

Nonscarring alopecias:

Miniaturization

Androgenetic alopecia (AGA)

Female Hair Loss: Ludwig Classification

Female Androgenetic alopecia (AGA)

Ludwig Stage I

Ludwig Stage II

Ludwig Stage III

• Androgenetic alopecia
• 50% of men and women experience androgenetic alopecia by age 50
• Each individual follicle is genetically marked to become bald or not to become bald
• Uptake, metabolism and 5-alpha reduction of testosterone to dihydrotesterone is increased in balding areas
• Hair miniaturizes with each cycle
• Treatment: oral finasteride, topical minoxidil solution, or hair transplant surgery

Alopecia areata (AA)

AA

 
AA

AA

AA and Vitiligo

AA

Pathogenesis of AA

Histopathology of AA

• Alopecia areata
  • Circumscribed oval circinate patch or patches; periphery may show short broken hairs
  • Exclamation point hairs which taper proximally can be seen and are pathognomonic
  • Asymptomatic, but there may be paraesthesias or tenderness
  • May affect eyebrows, eyelashes and beard
  • Course is unpredictable.  However, early age of onset and atopy may indicate a lengthy course with increased incidence of alopecia totalis.
  • 83% of all cases resolve in 3 years without treatment
  • 25% give a family history.  There are 2 sets of identical siblings that have had it simultaneously.
  • Associations: 8% thyroid disease, 4% vitiligo