Ringing on left side in left ear? can that be from allergies but without sinus pressure / blockage?

Ringing ear: This is unlikely allergy this could be due to wax blocking outer ear or fluid in middle ear. It can be due to nerve damage or even (in rare cases) tumors. Problems like this need to be checked by an ENT within days. Sometimes this can be serious and can lead to permanent hearing loss. Treatment may need to be started fast. Other causes could be trauma (i.e., loud noise damaging the ear).