Ive been having recurring armpit lumps in the same spot for almost a year! The lump grows in size and has severe pain. Then it disappears with no sign. The pain is worse a few days before periods, to the extent were am unable to move my arms. The extends to my shoulder and arms! This flare up occurs minimum 3 times a month! Also have associated rib pain while breathing or laughing! One of the lump formed pus and has been leaking pus for 2 months without healing. Took two courses of Augmentin 625 mg. Pre-existing condition- Arthritis (type not diagnosed yet) - get pelvic joint pain flare ups atleast monthly twice. Pains only when i move my legs. Doctor suggested that this could be auto immune related.