Hi My Name Is Cheryl, And My Podiatrist Told Me

Hi my name is Cheryl, and my podiatrist told me I had Plantar something. My feet have red spots, which he treated injecting steroids in both feet. (Very painful), and stated they were benign. One foot is seemingly healed, the other started healing, but now it has gotten redder and appears to have cuts on them, itchy and very painful. Is this condition caused by Diabetes? Is there any other treatment than the injections?