My 11 month old son has had a cough for the last 3-4 months. He just finished Augmentin for an ear infection 3 days ago. He continues to have a runny nose, which is colored in the morning and has a congested cough throughout the day. He has not had a fever since having the ear infection. Can he have allergies? And is Benadryl safe for him?

I have been told by the dotors that if he doesn't have colored nasal drainage or a fever it is viral?