For ich, slowly increase the temperature by about 2 degrees a day to 86 degrees. This is still within the comfort level for angels but should keep the ich from reproducing. Leave it at this temp. for about 2 weeks just to be sure. There will be less oxygen in the water so make sure there's plenty of surface agitation.
For the infection, I'm guessing pristine water quality, a good diet and time would be the best method. There's medications out there but I would wait to see if it's getting better or worse before buying anything.
Good luck.