My 6yr old has severe allergies. I gave home benadryl and Tylenol (acetaminophen) about 30 mins apart. But he has a cough. Can I give home delsym?

Exam. Before giving him a cough medication, have his lungs checked. If he has allergies he may be wheezing or have asthma. In that case his medication needs would be different. Also he may need different medication for his allergies. All the best.