Can you tell the difference between a cold and an allergy? Cold symptoms are very similar to sinus allergy symptoms. Both involve a runny nose, watery eyes, cough, nasal congestion, and sneezing. It’s tough to tell the difference. But there are 10 telltale signs that you have an allergy and not a cold. And by the way, kids with sinus and respiratory allergies are much more prone to ear infections, asthma, and sinus infections.