Hair on end sign (mnemonic)

The hair on end sign refers to a radiographic appearance of a skull which results from a periosteal reaction manifesting as perpendicular trabeculations interspersed by radiolucent marrow hyperplasia along the skull vault. It is classically described with plain skull radiographs although can also be appreciated on CT or MRI 3. Causes include:



  • hereditary spherocytosis
  • iron deficiency anaemia
  • neuroblastoma
  • enzyme deficiency, e.g. G-6-PD deficiency causing haemolytic anaemia
  • sickle cell disease
  • thalassemia major
Share article

Article information

rID: 9384
Sections: Signs, Mnemonics
Synonyms or Alternate Spellings:
  • Hair on end appearance
  • Hair-on-end sign
  • Hair on end appearances

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1
    Drag here to reorder.
  • Drag
    Lateral skull rad...
    Case 2: in thalassemia
    Drag here to reorder.
  • Drag
    Case 3
    Drag here to reorder.
  • Drag
    Case 4
    Drag here to reorder.
  • Updating… Please wait.

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.