I Have Had Auricular Perichondritis For Two Weeks Of Unknown

I have had auricular perichondritis for two weeks of unknown etiology. Because of stage 3 chronic kidney disease, I cant take aminoglycosides (also had tendon rupture on Cipro!) Have been on Ceftin 500mgm bid prednisone 10 mg 1 - 2 times a day for pain relief. No visible cutaneous disruption, but have applied gentamycin for a week then mupiricin with no improvement. Any suggestions ?