stretch mark vs stria

stretch mark

noun
  • Any of a series of red, irregular stripes on the surface of the skin caused by rapid growth of the tissues lying just underneath. They usually appear as a result of pregnancy, puberty or obesity, but can also be caused by rapid muscle growth. 

stria

noun
  • A stretch mark. 

  • A stripe, usually one of a set of parallel stripes. 

  • One of the fillets between the flutes of columns, etc.. 

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