Special Occasion Etiquette

Today my ward Graduated from High School.  We couldn't be prouder of him.  He had such a long journey to get to this point.  He will be leaving for the US Army come October.  However, there are a few issues for those with Celiac at these types of occasions.  As we were leaving the Graduation, The School officials tried to press a Cookie and lemonade into my hands.  I had to decline; in fact I wouldn't even touch the snacks.  I didn't want the gluten on my hand from the cookies and I had no idea of how, where or with what the lemonade was made.  This means that I couldn't safely consume anything.  While our Ward understood why I politely said no thank you and wouldn't let the snacks touch me, the person pushing them did not.  They only understood when I told them that I was allergic.