Hair Shaft Abnormalities Flashcards
What are the two broad categories of hair shaft abnormalities?
- Those associated with increased hair fragility
- Those not associated with increased hair fragility
What diagnostic methods are used for analyzing hair shaft abnormalities?
- Trichoscopy
- Light microscopy
- Reflectance confocal microscopy
- Transmission or scanning electron microscopy
What condition can be confirmed by amino acid analysis indicating low sulfur levels?
Trichothiodystrophy
What is ‘bubble hair’ and who is it commonly seen in?
‘Bubble hair’ is a hair shaft abnormality characterized by large irregularly spaced bubbles, usually seen in young women.
What can cause the formation of ‘bubble hair’?
Exposure to heat from hair care techniques on wet hair, leading to the formation of destructive bubbles.
What is monilethrix also known as?
Beaded hair
What genetic mutations are associated with monilethrix?
- KRT86
- KRT81
- KRT83
- DSG4 (for autosomal recessive form)
What are the additional manifestations associated with monilethrix?
- Keratotic follicular papules
- Syndactyly
- Nail abnormalities (e.g., brittle, koilonychia)
- Ocular abnormalities (e.g., juvenile cataracts)
- Dental abnormalities
What characterizes pili torti?
Flattening and 180° twisting of the hair shaft on its own axis
What disorders may be associated with inherited pili torti?
- Menkes disease
- Björnstad syndrome
- Bazex-Dupré-Christol syndrome
- Several ectodermal dysplasias
What is trichorrhexis invaginata commonly referred to as?
Bamboo hair
What syndrome is associated with trichorrhexis invaginata?
Netherton syndrome
What is the typical appearance of trichorrhexis nodosa?
Hair shaft fractures where cortical cells splay out, resembling the ends of two brushes pushed together.
What are the three clinical variants of acquired trichorrhexis nodosa?
- Proximal
- Distal
- Circumscribed
What is the inheritance pattern of trichothiodystrophy?
It is an autosomal recessive disorder characterized by sulfur-deficient hair.
What is the pathognomonic sign associated with trichothiodystrophy?
Tiger tail sign
What acronym is used to describe possible findings in patients with trichothiodystrophy types 1-3?
PIBIDS
- P (photosensitivity)
- I (ichthyosis)
- B (brittle hair)
- I (intellectual impairment with low IQ)
- D (decreased fertility)
- S (short stature)
What is acquired progressive kinking of the hair characterized by?
Acquired conditions characterized by curling of the scalp hair, presenting with curly, frizzy, and lusterless hair.
What is Trichorrhexis nodosa?
A hair shaft abnormality characterized by nodes along the hair shaft that weaken the hair structure. Excessive heat, chemical relaxation, frequent brushing or scratching.
Can lead to hair breakage and loss.
What is Trichorrhexis invaginata?
A hair shaft abnormality where the hair shaft is invaginated or folded back on itself. Ball and socket.
Also known as ‘bamboo hair’.
Found in nethertons
What is Monilethrix?
A hair shaft disorder characterized by alternating thin and thick segments along the hair shaft
Often leads to hair fragility and loss.
What is Trichoschisis due to trichothiodystrophy?
A hair shaft abnormality resulting from a defect in sulfur metabolism, leading to fragile hair with splits at the ends
Polarization is used for examination.
What is Trichothiodystrophy?
A genetic condition characterized by short, brittle hair that lacks sulfur
Results in various hair shaft abnormalities.
What is Bubble hair?
A hair shaft abnormality characterized by the presence of bubbles or cysts in the hair shaft
Can lead to hair breakage.
What is Pili torti?
A hair shaft abnormality where the hair is twisted or bent at regular intervals
Often observed under scanning electron microscopy.
What is Pili annulati?
A hair condition characterized by ringed or banded appearances in the hair shafts
Bright and dark bands are visible under reflected light.
What is Trichonodosis?
A hair shaft abnormality characterized by the presence of knots along the hair shaft
Can lead to hair tangling and difficulty in combing.
What is Pili trianguli et canaliculi?
A hair shaft abnormality characterized by triangular-shaped hair shafts with canaliculi
Best observed using scanning electron microscopy.
What is Trichoptilosis?
A condition commonly known as split ends, where the hair shaft splits into two or more strands
Often results from excessive damage or dryness.
What is the classic presentation of loose anagen hair syndrome?
A young girl with short blond hair and diffuse or patchy alopecia
Anagen hairs can be easily pulled from the scalp.
What are the microscopic features of loose anagen hair syndrome?
Ruffled proximal cuticle, absence of the root sheath, and a bent matrix
Abnormalities disturb normal anchoring functions.
What is a differential diagnosis for loose anagen hair syndrome?
Telogen effluvium, alopecia areata, trichotillomania, and short anagen hair syndrome
Short anagen hair syndrome is characterized by an increased number of telogen hairs.
Fill in the blank: Pili annulati is characterized by hair shafts that have _______ when viewed by reflected light.
bright and dark bands
True or False: Approximately 20%-80% of the hairs are affected in Pili annulati.
True
What happens to the bands in Pili annulati as they move distally?
The bands tend to disappear distally
This can affect the overall appearance of the hair.
