Inflammation of the lymph nodes behind the ear is usually caused by an upper respiratory tract infection, such as a viral or bacterial infection, that attacks the lymph nodes behind the ear. After the primary infection is controlled, the local lymph node inflammation will naturally resolve. In case of bacterial infection, antibiotics are mainly applied, commonly used for treating Gram-positive bacterial infections, such as amoxicillin, roxithromycin, clindamycin, or first- or second-generation cephalosporin antibiotics, and also oral Chinese medicines for clearing heat and detoxifying, anti-inflammatory and pain relief, such as Pudilan Oral Liquid or Blue Scutellaria Oral Liquid. If it is a viral infection, especially at the peak of influenza A, you can apply oseltamivir for antiviral treatment. You can also take Xiaojin pill orally, which has the effect of activating blood circulation, eliminating stasis and dispersing nodules, and also has a certain therapeutic effect on the enlargement of lymph nodes.