If you have an unexplained rash or itch, then it may be due to use of a mobile device, in particular the iPad.
Mobile devices contain nickel and that can irritate the skin.
It is thought that the contact is from a surface coating that contains nickel.
It is not life threatening, but it can be uncomfortable.
There have been recent reports in medical journals regarding nickel allergies from personal electronic devices,
Here’s a link to the story.