Delayed adverse skin reaction to transcutaneous electrical nerve stimulation (TENS) electrodes

A 76-year-old woman developed a delayed allergic reaction to adhesive pads following home use of transcutaneous electrical nerve stimulation (TENS) for pain management after a complex elbow dislocation. This case highlights the potential for delayed hypersensitivity reactions to TENS electrode pads. Although formal allergology testing was not performed, the woman's self-directed observations offered valuable insight. The clinical presentation and timing of symptom onset were more consistent with allergic rather than irritant contact dermatitis. Allergic contact dermatitis from TENS pads is often linked to specific allergens in the adhesive materials. Hypoallergenic alternatives aim to reduce this risk by eliminating or substituting known sensitizers. Interestingly, the reaction on the painful arm - where titanium plates had been surgically implanted - extended beyond the electrode placement, whereas on the unaffected, pain-free leg, it remained localized. This suggests that local tissue conditions may modulate the immune response. This case demonstrates the importance of clinician awareness regarding potential dermatological adverse events associated with TENS therapy and emphasizes the need for patient education, particularly when TENS is administered independently. Further investigation into the interaction between local inflammatory states and immune reactivity may inform safer electrode design and guide clinical recommendations for safe TENS use.