I don't think it is exactly a side effect. I am using it for a red, itchy (tiny blisters) that seems to spread from one location to another on myself. It started with my face, then went to my arms, and now on my hip areas and legs. My doctor said this should work, but not so far very effective. It is also very difficult to go about a normal day because by wearing your clothing the ointment does not stay on to well. My doctor now told me to keep on it, but it does not relieve itching very much.