• Blaschko lines are a distribution of skin lines which can be found in certain dermatosis, often genetic.
  • Examples include incontinentia pigmenti, epidermal nevus, lichen striatus…


  • These lines carry the name of Dr Alfred Blaschko (1858-1922), a German dermatologist who described the lines on a statue and published the pictoral diagram in 1901.


  • The cause of the lines is unknown, but one hypothesis is that they are the result of lyonization, X-inactivation which is a process by which one of the two copies of the X chromosome present in females (XX) is inactivated.



Source of information: Crissey JT el al. Dermatology and Dermatologists (2002). Parthenon Publishing