irritation vs psoriasis

irritation

noun
  • a state of inflammation or painful reaction to allergy or cell-lining damage. 

  • A things or person that annoys 

  • A condition of morbid excitability or oversensitiveness of an organ or part of the body; a state in which the application of ordinary stimuli produces pain or excessive or vitiated action. 

  • The state of being irritated 

  • The act of irritating or annoying 

psoriasis

noun
  • A noncontagious disease whose main symptom is gray or silvery flaky patches on the skin which are red and inflamed underneath when scratched. 

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