Hair loss may not seem like an Emergency to you… but it is! (Ok… maybe my perspective has changed as I’ve aged.) Seriously though, Alopecia will certainly catch a parent’s attention and they may just come to the ED for answers. Not that you need to have all of the answers pertaining to Alopecia, but let’s take a minute to ensure we have a useful perspective of Alopecia affecting Children:

Alopecia: Basics

• Hair consists of shaft and root, which is anchored in the hair follicle. [Xu, 2017]
  • Hair follicles contain rapidly dividing cells.
  • Hair follicles can produce different types of hair over their lifespan: [Atton, 1990]
    • Lanugo (soft hair newborns have)
    • Vellus (downy, fine hair that replaces lanugo)
    • Terminal Hair (thicker, pigmented hair)

• Every day 50-150 hairs fall out normally. [Xu, 2017]
• Terminal Hair goes through 3 growth phases: [Xu, 2017]
  • Anagen phase – active growth, 90% of hair
  • Catagen phase – brief involutionary phase
  • Telogen phase – dormancy, 5-10% of hair is in telogenic phase
  • Hair falls out after 2-3 months of telogen phase… and the cycle repeats.
• Hair loss can occur due to any disturbance in the development of a hair.

• Alopecia can occur in isolation or as a part of a multisystem syndrome. [Xu, 2017; Atton, 1990]
  • Nutrition and diet play a role (ex, Eating Disorders)
  • Autoimmune disorders (ex, Hashimoto Thyroiditis, Inflammatory Bowel Diseases).
  • Endocrine disorders (ex, Diabetes)
  • Atopic disorders

Alopecia: Considerations

• Alopecia is due to heterogenous etiologies. [Xu, 2017; Atton, 1990]
• Pediatric Alopecia is typically related to different causes than in adults. [Xu, 2017]
  • Majority of pediatric alopecia is due to acquired causes.
  • Although, it can even be present at birth (ex, aplasia cutis congenita).

• The common causes of Alopecia in children that should be considered: [Xu, 2017; Atton, 1990]
  • Tinea Capitis
    • Commonly due to Trichophyton tonsurans or Microsporum canis.
      • Microsporum species deposit a product that is fluorescent under UV light.
      • Trichophyton does NOT fluoresce and can produce lots of scaling and can be confused with seborrheic dermatitis.
    • Initially not scarring, but can lead to Kerion, which due to its local inflammatory reaction, can be scarring.
    • See broken hairs (i.e., Black Dot sign), scaling, erythema, and posterior cervical lymphadenopathy.
  • Alopecia Areata
    • Common form of autoimmune alopecia.
    • May have family history or personal history of other autoimmune disorders, like vitiligo or thyroid disease.
    • Typically has patchy hair loss that is well demarcated.
    • Has positive Hair Pull Test.
  • Trauma related:
    • Traction Alopecia
      • Due to constant tensile force on scalp from certain hairstyles (ex, braids, ponytails, tight buns, cornrows, etc).
      • Usually does not scar, but can if allowed to go one too long.
    • Trichotillomania
      • Associated with impulse control issues.
      • Non-scarring alopecia with patches of hair loss with irregular borders and hairs of various lengths.
      • Usually not including the occipital area (more painful to pull hair from this region.
  • Hair Cycle Disturbances
    • Telogen Effluvium – abnormal amount of hairs in the telogen phase leading to increased shedding and diffuse thinning without scale.
    • Anagen Effluvium – Rapid hair loss due to radiation/chemotherapy or malnutrition.
  • Transient Neonatal Hair Loss
    • Often concerning for first time parents, but is benign and common.
    • Occurs in first two months of life.
    • Previously thought to be due to friction of scalp on bedding, but this is unclear.
  • Numerous other odd and interesting causes that would delight a dermatologist (but that I can’t truly comprehend).

• Physical Exam can help distinguish etiologies: [Xu, 2017]
  • Look closely at scalp, lashes, dentition, and nails.
  • Try the Tug Test and Pull Test. [Xu, 2017]
    • Tug Test
      • Attempt to fracture the hair shaft… is the hair fragile?
      • Grasp the base of the hair and then tug the distal end with the other hand.
    • Pull Test
      • Gently pull a bundle of 20-60 hairs from multiple locations.
      • Positive Test if >10% are pulled out.

Moral of the Morsel

• Hair loss is not funny. (Stop laughing at me people!)
• Alopecia in Pediatric patients is often acquired. Look closely for clues and have a low threshold for covering for fungal infection.
• Hair Loss is not always simple. Think about related disorders and consider thyroid testing.

References