For my son it was all the H1N1 info spread at school in the beginning of the year. He wouldn't touch anything with his hands, including pizza, fries, and hamburgers. It took abit of educating and exposure to get through it. We also went through something similar during the New Orleans flooding. He was terrified of baths. There has been something that instigated this, maybe a class pet, or a peer having a death in the family. "We having nothing to fear but fear itself"