The British Association of Dermatologists (BAD) has issued an alert for Doctors to be aware of a new skin rash caused by long periods of mobile phone use.
In the warning the BAD links what is called "mobile phone dermatitis" to an allergic reaction of the phone's nickel surface. The rash typically occurs on the cheek or ear.
Doctors are being warned to be aware of the allergy, which is thought to be on the increase. Because the condition has only newly been identified, many cases may go unreported or untreated, which has prompted the scientists to share their findings.
Dr Lionel Bercovitch, of Brown University, Rhode Island, who was one of the study authors, said: "Nearly half of the phones we spot tested contained some free nickel.
"The menu buttons, decorative logos on the headsets and the metallic frames around the liquid crystal display (LCD) screens were the most common sites."
He added: "Given the widespread use of cell phones, the presence of metal in the exterior casing of these phones and the high prevalence of nickel sensitisation in the population, it is not surprising that cell phones can cause allergic contact dermatitis."
Women have a higher risk of developing mobile phone dermatitis, as they are more likely to have been previously sensitised to the metal following an allergic reaction to nickel jewellery.