A case of contact dermatitis caused by a cell phone grip ring

In recent years, as cell phone screens have become larger, their weight has increased. Here, we report a case of allergic contact dermatitis caused by metal grips used to hold a smartphone. A 29-year-old Japanese woman was referred to us with persistent eczematous lesions around the left middle finger (Figure 1A) 6 months after using a cell phone grip ring. Because she had a history of dermatitis caused by metal earrings and necklaces, we suspected allergic contact dermatitis caused by the ring as indicated by the eczematous lesion (Figure 1A,B). We performed a patch test using the Japanese metal allergy series (Torii Pharmaceuticals, Osaka, Japan) as well as a modified T.R.U.E. test (Sato Pharmaceuticals, Tokyo, Japan), according to the Japanese baseline series. Both tests showed a strong positive (++) reaction to nickel sulphate (Figure 1C) at 72 h. The patient stopped using the cell phone grip ring after the patch test and her symptoms were cured 2 months later. We then purchased a product of the same type and analysed the release of nickel using nickel spot testers (SmartPractice, AZ, USA). No nickel release was detected on the surface of the equipment when new; however, slight nickel release was observed when it was scratched (Figure 1D). The result of the experiment is consistent with her medical history. She lacked any symptoms when initially using the grip; however, as she continued to use it, her skin symptoms appeared. The reason why the erythema is more intense around the interdigital area is because there is more sweating, and the nickel can be released when the ring comes in contact with sweat (Figure S1). Grip rings are often used to hold smartphones. The European Union has regulations for accessories that come into direct contact with the skin, where nickel leaching must be below 0.5 μg/cm2/week.1 Following reports of nickel allergy from mobile phones,2 this regulation now also covers cell phones.3 Unfortunately, such regulations have not yet been implemented in Japan. Furthermore, these grips are still available from e-commerce sites in Europe, where strict metal regulations are in place. We think that products that come into direct contact with the skin for long periods of time, such as mobile phone accessories, should be regulated in the same way as rings and necklaces. Saki Ueda: Writing – original draft; resources; conceptualization; methodology; writing – review and editing; investigation. Kanako Akashi: Conceptualization; methodology; data curation; resources; writing – review and editing. Ken Washio: Conceptualization; methodology; data curation; supervision; writing – review and editing; writing – original draft; resources. We thank Dr. Hideki Shimizu (Shimizu Dermatology Clinic, Kobe, Japan) for referring the patient. We thank J. Ludovic Croxford, PhD, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript. The authors declare no conflicts of interest. Figure S1. Visualisation of sweating from interdigital and dorsal hand areas in a healthy volunteer using the modified Minor's method, note that more black dots are observed around the interdigital area (yellow arrows). Castor oil (Kozakai Pharmaceuticals, Tokyo, Japan) was mixed with potato starch. The mixture was applied 3 min after the povidone-iodine was applied, and photographs were taken 5 min later. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.