Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain first of all you should get properly evaluated for the exact cause of infection and the structures involved.. In case if there is swollen lymph nodes then it can be commonly due to infections in head and neck region and resolution in the size of lymph nodes will depend upon the resolution of the infection.. If the infection is in the salivary gland then antibiotics will only be advised.. Although both doxycycline and erythromycin are efficient enough to treat bacterial infections but should only be taken after a thorough clinical evaluation and a confirmatory diagnosis.. In case of lymph nodes a biopsy can be done to rule out the exact cause of swelling while in case of salivary gland a cross sectional x ray or an MRI can help in diagnosis of whether there is infection or duct obstruction due to stone formation.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.