Dr. Lawrence Glassman answered part of my question today (thank you) but did not respond as to whether I needed to take the 3 week course of erythromycin recommended by 2nd doctor who thought I was having an immune response.
Inflammatory reactions to fillers can rarely occur that are not well understood. If a low grade infection is suspected, then a course of antibiotics should be considered. The exact antibiotic and the length of treatment is determined by the patient's allergies, other medications taken, and clinical presentation.
Thank you for sharing your question and I am sorry to hear of your issues. Reactions to fillers can occur and based on your narrative I would continue to treat your undereyes with hyaluronidase to correct the issue. I do not think you need the antibiotics unless there is a concern of infection.