Iontophoresis uses an electric current to push a chemical compound through the skin. Most often a steroid such as dexamethasone (DEX) is used. DEX is a synthetic compound (not naturally occurring but manmade).
It has been used to treat many types of soft tissue problems. Achilles tendonitis, knee arthritis, and plantar fasciitis top the list. But it has also been used for carpal tunnel syndrome, myofascial syndrome, tennis elbow, and problems with the temporomandibular joint (TMJ).
It’s thought that the steroid passes through the skin through the pores in the skin. Once it gets past the skin, blood and diffusion carry it the rest of the way to the soft tissues such as tendons, fascia, or the bursa.
It works by reducing the effects of immune cells capable of setting up an inflammatory response. By suppressing the immune system at the cellular level, DEX decreases pain and increases function.