My Son Has Reactive Arthritis Secondary To Elevated Strep Levels.

My son has reactive arthritis secondary to elevated strep levels. He has been being treated with a low dose of erythromyosin for the last six months because he is allergic to penicillin. His numbers have gone from 579-549-604 and he recently had another strep throat. His rheumatologist is upping the dosage of meds for 1 month to see the effect. What can he do to help? Dietary changes? alternate natural treatments etc