bejel vs impetigo

bejel

noun
  • Endemic syphilis, a chronic disease of skin and tissue caused by infection by a subspecies of the spirochete Treponema pallidum. 

impetigo

noun
  • A contagious bacterial skin disease forming pustules and yellow crusty sores, chiefly on the face and hands. It is common in children and infection is often through cuts or insect bites. 

How often have the words bejel and impetigo occurred in a corpus of books? (source: Google Ngram Viewer )