The enlarged lymph node
could be because of the ear infection
I hope that there is enlarged lymph node and not the parotid gland
disease does not cause pre auricular lymph node enlargement.
If it is a enlarged lymph node only and nothing elese then you need to get your ears examined and take a 10 day course of antibiotics and still the lymph node does not go, then there are less chances of infection--
then you might need a Fine needle aspiration cytology of the node to see the microscopic structure of the node and see that this is because of infection or not.