Hello, Naomi and welcome!My name is XXXXX XXXXX it will be my pleasure to assist you and Mew today.I'm sorry he's having this problem.From your description, if you're sure he doesn't have fleas, it sounds like he may have some type of mites which do burrow under the skin and cause itching. There are two types: demodectic mange mites and sarcoptic mange mites. Here is more detailed information:http://pets.webmd.com/cats/cat-mange-scabiesA good next step would be to have the vet evaluate him in person and take a skin scraping (painless) to determine the cause of this itching and then prescribe treatment.It's also possible that he is experiencing an allergic reaction to something in his food or to something he is coming in contact with inside and/or outside, so the vet might want to do some allergy testing, as well.Sometimes, you don't have to see any fleas to have a cat experience an allergic reaction to just one bite. A condition that can come from this and other sources is called Miliary dermatitisAlso, from your description of him flinching and running around the house when he feels itchy, if he's also trying to bite at his back and/or tail and his skin is 'rolling' or 'crawling', this could be an indication he has developed feline hyperesthesia. Here is more information: HyperesthesiaYou could treat with a monthly flea preventative sold by your vet, to see if this will help, but since it's applied to the back of the neck/top of the back area, you don't want to put it there at this time if he has open sores.Discuss these possibilities and treatments with your vet and I hope Mew is feeling much more comfortable, very soon.
If it's some type of mites, are transmitted to other cats or people?...because we have another cat in the home and he's just fine.
Mew is actually doing much better. We decided to change the food he had been eating for many years. The bumps around his neck have nearly dissappeared. He's much more like himself now. Either way we are taking him in to the vet next week.