What is this?

I've read through a few posts and also through a few links mentioned here, but was still hoping to get some input on the situation. Keep in mind I'm writing from a hotel, and my mom told this to me over the phone.

My one cat has scabs around his neck, and I don't know why. He's not biting or scratching himself like something is biting him, and my other cat doesn't have anything like that on his body.

The cat that has the scabs around his neck is declawed, whereas the other cat has claws, and is younger. I don't know if perhaps they are fighting or if it's fleas, or something like that. I feel bad for not knowing what is going on XD My job doesn't help the situation because I am away for days at a time from my apartment, so it will be at least a week before I can get back home to take my cat to a vet.

It could be any number of things.From fleas,to an allergic reaction to something,to mange.
I found that even if you don't see fleas, sometimes you still have them.
I would suggest taking the cat to the Vet for a diagnosis.Good luck!

I agree that a vet will be able to diagnose this, though it may involve doing a test the way we did with Gizmo (a hair pulled from the edge of her bald patches yielded a diagnosis of fungal infection and she has to take medication.)