alopecia
ALOPECIA

Alopecia is an involuntary loss of hair usually in the scalp that may occur anywhere over the body.
Scarring alopecia is severe inflammation of the hair follicle result in irreversible damage.
Non-scarring alopecias are reversible.
Alopecia may  be abrupt or gradual in onset.
Most common causes include androgenic alopecia (male & female pattern baldness) & alopecia areata.
History should be reviewed for medications, severe diet restriction, vitamin A supplementation, thyroid symptoms, concomitant illness & stress factor.

Introduction

  • May be localized (patchy) or generalized
  • Scarring or non-scarring
    • Scarring alopecia from severe inflammation of the hair follicle result in irreversible damage
    • Non-scarring alopecias are reversible
  • Abrupt or gradual onset
  • Most common causes include androgenic/androgenetic alopecia (male and female pattern baldness) and alopecia areata
  • History should be reviewed for medications, severe diet restriction, vitamin A supplementation, thyroid symptoms, concomitant illness and stress factor

Definition

Alopecia areata
  • Autoimmune hair follicle disease characterized by patches of significant hair loss
Androgenic alopecia
  • A chronic follicular disorder characterized by progressive hair loss with a patterned distribution
  • Alopecia totalis mimics androgenic alopecia

Signs and Symptoms

Androgenic alopecia in males/females
Patterned hair loss
  • Hamilton-Norwood staging [male pattern hair loss (MPHL)]
    • The higher the stage, the more severe the hair loss
    • Usually starts with bitemporal recession of frontal hairline and continuing with thinning over the vertex, eventually complete hair loss on the vertex; bald hair
    • The bald patch enlarges and joins the receding frontal hairline
    • Other patterns may develop, but it is the androgenic-independent hair (on the sides and back of scalp) that do not thin
  • Ludwig staging [(female pattern hair loss (FPHL)]
    • Marked presence of miniaturized, vellus-like hair follicles
    • The higher the stage, the more severe the hair loss
    • Thinning usually diffuse, but more marked on the frontal and parietal regions; “monk’s haircut” in severe cases
  • Christmas Tree Pattern
    • Another female hair loss pattern with centroparietal thinning and frontal accentuation
Age of onset
  • Thinning of the hair begins between 12-40 years for MPHL
  • Chronic progressive diffuse hair loss in their 20’s and 30’s for FPHL
Alopeica areata
Clinical presentation
  • Non-scarring with hairs located at the periphery of the patch extending a few millimeters above the scalp (“exclamation mark”) hair
  • Nail dystrophy occurs in 10%
    • Pitting with irregular pattern or organized transverse or longitudinal rows, concave dorsal nail plate, etc
  • 100% loss of scalp hair (alopecia totalis), 100% loss of hair on scalp and body (alopecia universalis)
Age of onset
  • Most patients are <40 years of age
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