A patient is being treated with iontophoresis, driving dexamethasone, for inflammation around the lateral epicondyle of the left elbow. The PTA is careful when setting the parameters and with cleaning the site of electrode application to prevent a possible blister. This possibility is not as strong with some forms of electrical stimulation, but because iontophoresis uses this form of electrical current, precautions must be taken to ensure that the patient does not receive a mild burn or blister during treatment :