II. Pathophysiology
- Hair breakage due to Trauma or fragile hair
- Primarily affects proximal Hair Shaft
III. Causes: Trauma
- Excessive brushing
- Excessive scalp scratching
- Excessive salt water exposure
- Heat application
- Tight hair styles (e.g. Traction Alopecia)
- Trichotillomania
- Chemical use on hair (e.g. excessive bleach, dyes, Shampoos, perms, hair relaxants)
IV. Causes: Systemic, congenital, or genetic disorders leading to fragile hair
- Trichorrhexis invaginata (bamboo hair)
- Hair shaft Intussusception (at keratinization zone)
- Menkes Disease
- Abnormal copper metabolism (results in keratinization defect)
- Argininosuccinic aciduria
- Hypothyroidism (rare cause)
V. Signs
- Broken hairs along proximal shaft that split into strands
- Hairs appear as white nodes or knots on gross exam
VI. Labs: Optional (as indicated, in older patients not using hair treatments)
- Complete Blood Count
- Serum Iron and Serum Ferritin
- Copper level
- Liver Function Tests
- Thyroid Stimulating Hormone (TSH)
- Serum and urine Amino Acid level
VII. Management
- Eliminate physical and chemical Trauma to the hairs