Can Azithral Treat High Fever And Rashes?

i am in india,my16 yr old son had high fever for 2 days, the 1 st day he was prescrbed meftal 250 mg every 6 hours and azithral 500 mg, he has rashes pretty big like moquito bites on his face,chest and back the fever has gone but the rashes are still thereon his face and back the doctor suspected allergy and gave him some antihistamine too