7 yr old type 1 diabetic becoming germaphobic? Help!

My 7 year old son has had Type 1 diabetes for 3 1/2 years now. Ever since his last "major" illness (stomach flu) last November, he has been totally freaking out at even the thought of germs. If someone sneezes, he runs to another room. I am even hearing now that when he goes to the nurse's station at school for his bg checks and dosing, he refuses to sit in a particular chair because "sick kids sit there, and there's germs there". It's almost to the point where I'm concerned it might be causing some anxiety issues with him (which he has had, what we are describing as, an anxiety attack in school on two occations so far this year.) Has anyone else ever experienced this? Any thoughts on how I can help him be aware of germs, but not become overly concerned to the point of risking possible mental health concerns? Thanks in advance!!