We have a small cat (not kitten) which appears to have some sort of skin infection. It has small bumps all over its skin. Like little red pimples. It does not appear to have fleas and has been wormed regularly.
It could be a flea allergy, you say he doesnt 'appear' to have fleas but when did you last de-flea him? Even if he is flea free it can take just one flea bite to cause irritation.