Brief answer viral fever Detailed answer hi greetings If i were your doctor instead of changing medicine so frequently i would have advised you some non medical measures along with the early course of antibiotics like warm saline gargles, steam inhalation and deep breathing exercises I would also suggest him to have tab vitamin C and other multivitamins to boost his immunity to fight against invading pathogen Please ask your doctor X Ray paranasal sinuses and complete blood count supportive care may help you lose anti allergic medicines with or without local spray hope this information will help you wish you good health regards