hello.. thanks for writing to us. Epididymitis is an infection, inflammation of epididymis (a structure in testes of males which stores sperms) it is commonly caused by chlamydia, gonorrhea and E.coli. and usually preceded by urinary tract infection. most common symptoms include pain, burning and swelling of affected testes. some patients have fever and burning urination also. In case of your son, you said it is chlamydia infection which is better treated with antibiotics like Azithromycin, cephalosporins. Doxycycline is usually recommended as a secondary line of treatment. If a similar case walks into my clinic, i would have prescribed Tab. Azithromycin 500mg along with anti-inflammatory drugs like ibuprofen twice daily for four weeks. Cold compression can be applied to the scrotum which gives relief from pain, burning and swelling. I suggest you to talk to your treating doctor about the recurrence and change the antibiotic. hope my answer helped. thank you.