formication vs tickle

formication

noun
  • An abnormal skin sensation similar to that of insects crawling over or within the skin; a tactile hallucination involving such a sensation. A common side-effect of substance abuse, it can also be experienced with high fever, menopause, skin cancer, diabetic neuropathy, or herpes zoster. 

tickle

noun
  • An itchy feeling resembling the result of tickling. 

  • A light tap of the ball. 

  • The act of tickling. 

  • A narrow strait. 

verb
  • To appeal to someone's taste, curiosity etc. 

  • To unexpectedly touch or stroke delicately in a manner which causes displeasure or withdrawal. 

  • To catch fish in the hand (usually in rivers or smaller streams) by manually stimulating the fins. 

  • To touch repeatedly or stroke delicately in a manner which causes laughter, pleasure and twitching. 

  • To cause delight or amusement in. 

  • To feel titillation. 

  • To feel as if the body part in question is being tickled. 

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