iPhone charger-induced chemical burn from overnight contact with sweat: Two cases.

Smartphones have become essential devices in modern society. The coverage rate of smartphones in 2017 in Japan was 75% according to the Ministry of Internal Affairs and Communications. The iPhone is one of the most well-known smartphone brands. According to the manufacturer of iPhones (Apple), more than 200 million iPhones had been sold worldwide by 2017. These devices are often charged at night-time, especially while being used in bed. There are only three reports of smartphone charger-induced skin damage. We present two new cases of skin ulcers induced by an iPhone charger. The iPhone's "lightning cable" has electrodes outside, and we found that this can present a higher risk of causing a skin injury compared with other types of phone chargers. We also investigated the mechanism of the skin ulcers caused by the iPhone charger. The results indicated that these ulcers were chemical burns rather than an electrical injury or heat-induced burn.