What Causes Swelling Of Ankles And Feet With Itchiness?

Hi, my 94 yr old grandmother has very swollen ankles and feet, about 3 months ago she started getting itchy sores on her arms, they are now on her head, seems to be in upper torso area where there is hair. I have taken her to a dermatologist, and the family Dr. They put her on an antibiotic, prednisone and a anti-fungal cream. Does not seem to be making any difference, and now this swelling of the feet and ankles has me perplexed, can you help?