Smartphone manufacturers use a series of components to build their products. Nickel and chromium are among them. Both these metals are known allergens, and, according to research, the amount released from smartphones is enough to induce acute contact dermatitis.
People with nickel allergy develop itchy rashes on their hands, cheeks, and ears – the three areas of the body where the smartphone is mostly in contact with.
It is worth mentioning that people with metal allergies will be sensitive to these items for the rest of their lives. In this specific case, you can overcome this problem simply by using a protective case made from another material.