Introducing iontophoresis

Corticosteroid injections are a common and effective short-term treatment for inflammatory problems occurring in damaged muscles and tendons. The injections simply calm down the inflammation to the point where healing of the affected area can take place. Aside from the negative effects of prolonged steroid treatment, the biggest complication with this treatment is the fact that it’s invasive. You have the general problems that can occur when you put a needle anywhere, including pain, unwanted irritation, infection, and accidental injury. Because topical applications of steroids don’t penetrate the skin well, a middle ground is needed for transdermal delivery in situations where a needle isn’t wise.

Iontophoresis might be that middle ground. This treatment involves the use of an electrical field to deliver medication through the skin and into underlying tissues. The medication is charged so that it’s pushed into the skin by an active electrode, and its molecules are small enough that it “soaks” into the treatment area. I use “medication” here generally because the method has uses beyond anti-inflammatory treatments.

Iontophoresis does have drawbacks. It takes a while to administer (around thirty minutes seems typical), it can cause discomfort, and it can interfere or react with medical implants. When used with corticosteroids, it can hinder the body’s healing mechanisms. Perhaps the biggest drawback is that like many aspects of physical therapy, iontophoresis is being figured out on the fly. The technique has been around for decades, but researchers are still debating its merits and best practices. The varieties, doses, and combinations of anti-inflammatory treatments used could be turned into a cocktail book, and the application procedures are nearly as varied. Of course, the commonly accepted model of tendon damage/inflammation is under some scrutiny lately so that may have some bearing on how this treatment is ultimately viewed.


I underwent three rounds of iontophoresis a few months ago for an aggravated nerve/tendon issue that I’m having with both arms. I’ll admit that I was feeling a bit desperate when I agreed to the procedure after my physical therapist advised it. I’d spent months trying to find a specific cause for the problem without success. I had hoped that multiple anti-inflammatory treatments would knock out any self-sustaining nerve inflammation and maybe pull back the curtain on an underlying problem that was being masked by inflammation but to no avail. All I had to go on for the iontophoresis was my doctor's recommendation, a recollection that Mike Reinold (physical therapist for the Boston Red Sox) liked the treatment, and a vague memory that it was a polarized-deposition technique. That was it.

Because my problems were centered on my ulnar nerve, iontophoresis was a good way to avoid accidentally jamming a needle through a major nerve. More specifically, the issues I’m having originate around the medial epicondyle, which is the bony knob on the inside of the elbow. The treatment would be directed at the bundle of tendons just above the epicondyle. The prescribed cocktail was a mix of dexamethasone (a synthetic corticosteroid) and lidocaine. I was told the lidocaine wasn't used for its anesthetic effects but because it enhanced the iontophoretic movement of the medication. Though I didn’t follow up on this, lidocaine works on nerves by blocking charged channels in their cell membranes. Because cell membranes use polarization as a way of admitting/blocking foreign materials, my guess is that this is the mechanism for improving the dexamethasone’s distribution.

At risk of dating myself, the iontophoresis device itself was about the size and shape of a Walkman and the electrodes resembled oversized earbuds. The treatment itself was performed with me on my back. I removed my shirt and tie for treatment, though you can leave anything on that isn’t near the treated area. After getting swabbed with alcohol, the electrodes were applied to each arm. After application, my arms were bent with the upper arm resting against the bed and the lower arm draped across my body. I lightly hooked my fingers around my belt to keep them from fidgeting.

The device was started and left beside me along with a timer. The feeling of the machine isn’t the full-on hyper-vibrating tingling sense you’d get from an EMG. It was more of a mild, prickly sting that faded after the first few minutes. My physical therapist said that some people couldn’t feel the current at all while others found it too unpleasant to deal with. The electrodes left reddened, irritated patches that didn’t bother me and faded pretty quickly.

The biggest downsides to the treatment were entirely distinct from medical outcomes. First, I had to lie still for twenty minutes—and I mean completely still. I was able to stay mentally busy, so boredom wasn’t a problem once I got settled in. You could probably listen to music without a problem if you chose. However, even the slightest movement would disconnect the electrodes’ wires from the device. I managed to disconnect them twice—first by slightly retracting my shoulder blade and second by taking a slightly deep breath. (I’m not kidding.) I’m thinking it’s an intentional design feature for some reason, so if you get the treatment, keep this in mind. I had to go into half-ass meditation mode to ignore a nose itch at one point. I thought about bringing a stick with me to reach my face but figured that even just wiggling my wrist would probably free the wires.

As far as outcomes, I noticed an immediate reduction in my nerve symptoms after the first treatment. After the second treatment, the prickling/tingling I’d been dealing with during daily life was almost completely absent. The third treatment dulled the problems a little more though didn’t eliminate them. Unfortunately, it didn’t kick the problems completely or provide more insight into the underlying cause of what’s going on. Still, post-treatment symptoms have been (and continue to be) far better than they were before the treatment, so I feel like it was more than worth the effort. I’m going to get more specialized in the next few months and see if I can’t kick it for good.

There’s one final catch I want to cover. I wasn’t kidding when I said that the research is a little behind on iontophoresis. My insurance provider (and several others I’ve come across) doesn't cover iontophoresis when it’s used as an anti-inflammatory. I’m not going to rage against the insurance industry on this one because there really isn’t that much evidence for it. People are still referring to proof-of-concept studies (which show that iontophoresis just gets the medicine into the tissue as opposed to working against inflammation) as hot items.

Wrap up

My measure of success with the dexamethasone/lidocaine treatment may have been a placebo or an outlier. I think the former is unlikely but the latter a distinct possibility. That said, my final take is that iontophoresis is a useful treatment under the right circumstances. That’s a vague approval of course because the body of evidence is building toward an ideal usage scenario.