I was playing with a cat last night in a hotel. He really took a shine to me. I was flattered because cats normally can tell I think of them as inferior dogs, and therefore usually ignore me. I was playing with him absent-mindedly for ages. As I got up to leave, I scratched him on top of his head and I recoiled instantly. He had lots of tiny really hard lumps on top of his head and they felt minging. All fo today I've have tingling and itching felling on my own head and scalp. I think I have caught something. What can it be?