The back of the foot blisters are itchy, this situation may be an allergic reaction to the back of the foot, it may be contact dermatitis, it may also be insect bite dermatitis. 1, if the allergic factors are caused, you can topically apply glucocorticoids to stop the itching. The actual fact is that you can get a lot more than just a few of these. This time you need to apply antibiotics topically, you can apply fusidic acid cream, mupirocin cream, at the same time need to take oral antibiotics for treatment, generally can take oral roxithromycin or cefadroxil capsules and so on.