Hi there. I also have an almost three year old son with tics. He has a history of milk soy protein intolerance as a baby, he gets croup every time he is sick, and we suspect asthma and allergies. We tested him with skin pricks last year at the age of two and his histamine was high but nothing else was positive. he started with eye blinking last April. It lasted a month and we were told it was a tic. It came after an ear infection. After it went away for six months it came back after another croup illness last October. Went away for a few months and now it came back with a vengeance.