fever pitch vs excitation

fever pitch and excitation both are nouns.

Word	Noun	Adjective	Verb	Adverb
fever pitch	Yes	No	No	No
excitation	Yes	No	No	No

As nouns, excitation is a hypernym of fever pitch; that is, excitation is a word with a broader meaning than fever pitch:

Other hypernyms of fever pitch include excitement, fervor, fervour, inflammation.

fever pitch (noun)	excitation (noun)
a state of extreme excitement	something that agitates and arouses
	the neural or electrical arousal of an organ or muscle or gland
	the state of being emotionally aroused and worked up