Burn Wound After Use of a Transcutaneous Electrical Nerve Stimulator (TENS) with Foot Bath--A Case Report

Introduction: Transcutaneous electrical nerve stimulator (TENS) units transmit low-voltage electrical impulses to an area of the body and are often utilized as an adjuvant treatment for pain (1). Burns have been reported as a complication of TENS and sensory neuropathy is a contraindication to the treatment (2). We report a case of important burns to the feet in a diabetic patient who was treated with TENS and an immersive foot bath.

Case Presentation: A 62-year-old male with a history of Type 2 diabetes presented to an outpatient wound center one week after suffering burn wounds to his feet. He had initiated treatment with TENS for his diabetic peripheral neuropathy, from which he had total loss of sensation. The device included a twin compartment foot bath in which the feet were submerged into a conductive electrolyte solution and stimulation pads were placed into the solution. After a second 30 minute session of treatment, the patient noted redness and blistering of the skin on his right foot. On exam the patient had a circumferential burn injury of the right foot with blistering and eschar. Semmes-Weinstein testing showed no sensation in the feet. Superficial debridement was performed and standard burn wound treatment was initiated with daily silver sulfadiazine cream application.

Conclusion: The reported case represents an important complication of TENS. The conductive solution in the foot bath was likely heated to a temperature sufficient to cause injury, and the patient was unaware due to his lack of sensation. Burn wounds have been reported at the sites of electrode placement in TENS (1), but this case represents the first noted with the use of an immersive foot bath. Such devices are available for commercial sale, and while approved for pain relief, some have proposed without strong data potential benefits in returning nerve sensation (2). The above case demonstrates the risks (and contraindication to) the use of TENS in the context of sensory neuropathy, especially with an immersive foot bath. Practitioners treating patients with peripheral neuropathy should be aware of this potential complication and caution patients who might pursue this form of treatment.