A practical, algorithmic approach to diagnosing hair shaft disorders

Int J Dermatol. 2011 Jan;50(1):1-12. doi: 10.1111/j.1365-4632.2010.04768.x.


The hair shaft is a unique structure composed of an inner cortex and a protective outer cuticle. Any defects in this normal structure due to genetics or the environment can lead to variations in physical properties. Thus one should suspect a hair shaft disorder if a patient presents with an abnormality or change in hair texture, appearance, manageability or ability to grow hair long. A key feature of the clinical evaluation is to determine whether there is hair breakage (increased fragility) by looking for broken hairs and performing a tug test. Once this determination is made, an algorithmic approach can be used to narrow the differential diagnosis: hair shaft disorders with and without fragility. A hair mount along with other directed questions and examination will almost always allow the clinician to make an in-office diagnosis. Common case scenarios, photographs, and practical tips are provided to illustrate the use of this algorithmic approach in the diagnosis of hair shaft disorders. We have also included a summary of the molecular defects where known, which can be helpful in providing a correlation with clinical findings, in counseling patients, and potentially offering treatment options.

Publication types

  • Review

MeSH terms

  • Algorithms*
  • Child
  • Female
  • Hair / abnormalities*
  • Hair / chemistry
  • Hair / pathology*
  • Hair Diseases / diagnosis*
  • Hair Diseases / pathology
  • Hearing Loss, Sensorineural / diagnosis
  • Hearing Loss, Sensorineural / pathology
  • Humans
  • Male
  • Mitochondrial Diseases / congenital

Supplementary concepts

  • Bjornstad syndrome