Bacterial infections I treat at 75 degrees and I also like kanamycin for an antibiotic. 86 is just a crazy temperature for treating bacterial infections. I'd drop it as low as the discus can tolerate temporarily.
With a bacterial infection High temps is not always the best thing to do because it may rapdily reproduce. But, with that said if you were treating with the proper meds and in a QT tank with clean pristine water conditions higher temperatures will help speed up the metabolism and immune system of the fish to help fight the disease.
It's been 5 days since this was posted and he was 5 days into the issues... I hope for the best for these guys!