My 9 months old boy complain of raining nose and high temp , can i use antihistamin with the temp reliever ?

Runny nose: The runny nose is probably from an infection and the antihistamine may dry it up a bit but would not be my first medication choice in that condition. A saline nasal spray should help with the nasal symptoms better.

Temp reliever: You may use tylenol (acetaminophen) to keep a high fever down but the antihistamine would not do much even though it may have a minimal effect on reducing the runny nose if you use Benadryl or chlortrimeton.