Wearable Health Device Dermatitis: A Case of Acrylate-Related Contact Allergy

Mobile health devices enable patients and clinicians to monitor the type, quantity, and quality of everyday activities and hold the promise of improving patient health and health care practices.¹ In 2013, 75% of surveyed consumers in the United States owned a fitness technology product, either a dedicated fitness device, application, or portable blood pressure monitor.² Ownership of dedicated wearable fitness devices among consumers in the United States increased from 3% in 2012 to 9% in 2013. The immense popularity of wearable fitness devices is evident in the trajectory of their reported sales, which increased from $43 million in 2009 to $854 million in 2013.² Recognizing that “widespread adoption and use of mobile technologies is opening new and innovative ways to improve health,”³ the US Food and Drug Administration (FDA) ruled that “[technologies] that can pose a greater risk to patients will require FDA review.” One popular class of mobile technologies—activity and sleep sensors—falls outside the FDA’s regulatory guidance. To enable continuous monitoring, these sensors often are embedded into wearable devices.

Reports in the media have documented skin rashes arising in conjunction with use of one type of device,⁴ which may be related to nickel contact allergy, and the manufacturer has reported that the metal housing consists of surgical stainless steel that is known to contain nickel. We report a complication related to continuous use of an unregulated, commercially available, watchlike wearable sensor that was linked not to nickel but to an acrylate-containing component.

Case Report

An otherwise healthy 52-year-old woman with no history of contact allergy presented with an intensely itchy eruption involving the left wrist arising 4 days after continuous use of a new watchlike wearable fitness sensor. By day 11, the eruption evolved into a well-demarcated, erythematous, scaly plaque at the location where the device’s rechargeable battery metal housing came into contact with skin (Figure 1).

Figure 1. Localized geometric eczematous dermatitis at one site on the left wrist in close contact to the wearable device.

Dimethylglyoxime testing of the metal housing and clips was negative, but testing of contacts within the housing was positive for nickel (Figure 2). Epicutaneous patch testing of the patient using a modified North American Contact Dermatitis Group patch test series (Table) demonstrated no reaction to nickel, instead showing a strong positive (2+) reaction at 48 and 72 hours to methyl methacrylate 2% and a positive (1+) reaction at 96 hours to ethyl acrylate 0.1% (Figure 3).

Figure 2. The metal housing for this wearable device (point A). Within the well is the rechargeable battery component (point B).

Figure 3. Degree of patch test positivity at 72 hours showing a strong positive (2 ) reaction to methyl methacrylate 2% and a weaker reaction (1 ) to ethyl acrylate 0.1% at 96 hours.