Alopecia Areata

Snapshot

• A 35-year old woman with a past medical history of atopic dermatitis comes to the dermatologist for multiple, round patches of balding on her scalp. She has had more and more of these bald spots for about 2 months. She cannot recall any instigating events and denies pulling out her hair intentionally. Physical exam reveals no inflammation or erythema in the affected areas. A punch biopsy reveals lymphocytic infiltration. She has a family history of rheumatoid arthritis and Grave’s disease. 

Introduction

• Chronic, autoimmune non-scarring hair loss disorder
  • as opposed to scarring cicatricial alopecic disorders such as discoid lupus or lichen planopilaris that lead to destruction of hair follicle
• Epidemiology:
  • rare (1.7% lifetime risk of developing disease)
  • affects males and females equally
  • affects children and adults equally
• Associated conditions:
• other autoimmune diseases, especially thyroid and atopic disorders 

Presentation

• Symptoms:
  • smooth, discrete, circular patches of hair loss that are typically without pain or itchiness
  • can spontaneously regrow hair or spontaneously progress to alopecia totalis/universalis
  • no erythema, inflammation, or scarring
• nail abnormalities are common, including pitting of nail plate

Evaluation

• Clinical evaluation of hair loss sites
  • “exclamation point hairs” at margins of patches
    • short, broken hairs that narrow at the base
    • extracted easily
    • low sensitivity
• Punch biopsy
  • peribulbar lymphocytic inflammatory infiltrates surrounding follicles
• Laboratory studies normal

Differential Diagnosis

• Tinea capitis 
• Trichotillomania (nervous hair pulling)
• Androgenetic alopecia
• Cicatricial alopecia
• Telogen effluvium
• Traction alopecia
• secondary to hair tension that is prolonged or repetitive

Treatment

• Watchful waiting for mild cases, as hair may regrow spontaneously
• Limited therapies available; all with limited efficacy
  • intralesional corticosteroids (triamcinolone)
  • topical steroids
  • pulsed prednisone
  • topical immunotherapy
• Currently under investigation: targeted immunotherapies
• janus kinase inhibitors tofacitinib, ruxolitinib 

Prognosis, Prevention, and Complications

• Variable, unpredictable pattern of regrowth, patchy hair loss, and progression to alopecia totalis or universalis