Looked in baby's ear and ear drum is red on one ear he is teething and runny nose could it b ear infection or pressure?4 weeks ago on antibiotics

Red doesn't diagnose: Red is but one thing we look at when visualizing an ear drum. Red alone does not an ear infection make. An ear drum can be red if child has fever, is crying, holding breath, etc. We also look at landmarks, how the light reflexes, whether the ear drum moves, whether there is fluid behind the drum. All the things together make the diagnosis. If you are concerned, best to have doc look to diagnose.

See Pediatrician: May be return of ear infection. Runny nose may be due to teething, if it's upper tooth trying to erupt, but may also be due to whatever is causing ear problem. Please call your Pediatrician now.