septic sore throat vs throat infection

septic sore throat and throat infection both are nouns.

Word	Noun	Adjective	Verb	Adverb
septic sore throat	Yes	No	No	No
throat infection	Yes	No	No	No

As nouns, septic sore throat and throat infection are synonyms defined as:

septic sore throat and throat infection: an infection of the oral pharynx and tonsils by streptococcus

Other synonyms of septic sore throat include strep throat, streptococcal sore throat, streptococcus tonsilitis.

septic sore throat (noun)	throat infection (noun)
an infection of the oral pharynx and tonsils by streptococcus	an infection of the oral pharynx and tonsils by streptococcus