Rescued puppy won’t stop itching (NOT FLEAS)

I recently rescued a puppy from a shelter. They told me when they first got him that he had a mild case of fleas and that over the last 3 weeks he’s been on multiple treatments for them and in the last week they hadn’t found any on him. However when I brought him home I noticed he won’t stop itching a few spots so I thought he must still have fleas, however I’ve gone over every inch of him with a comb, flashlight and camera and haven’t found any signs of fleas, no dead fleas, no eggs, No nothing (he’s relatively short haired so I can see down to his skin perfectly) . However I have noticed he’s pretty dirty so I’ve chalked up his itching to just being dirty, also in the places he’s itching he does have healing cuts so it’s possible those could be itching too. The problem is I can’t give him a bath for atleast another week 1/2 because he was neutered on the 13th and they say his stitches can’t be wet, I got some wipes and have been wiping him down to help cause he smells, is there anything I can do to help his itching until I can give him a bath? I feel terrible for the little guy 🙁