Mobile phone users could develop rashes on their faces and ears due to an allergic reaction to nickel on handsets, skin experts have warned.

Nickel allergies are the most common in the UK and are thought to affect a third of the population. It is often found in the handset casing or buttons.

The British Association of Dermatologists (BAD) and scientists at Brown University, Rhode Island, said the trend is being seen in people who spend long periods of time on the phone. It warned that women who reacted to nickel in jewellery were at a higher risk of a rash from their phones.

It also said people who spent a lot of time texting could develop the rash on their fingers as a result of touching the metal menu buttons.

Dr Graham Lowe, from BAD, said: “The allergy results from frequent skin contact with nickel-containing objects. Prolonged or repetitive contact with a nickel-containing phone is more likely to cause a skin reaction in those who are allergic.

“In mobile phone dermatitis, the rash would typically occur on the cheek or ear, depending on where the metal part of the phone comes into contact with the skin.”

The link to mobile phone handsets was identified in several published case reports of patients with unexplained rashes on their face and ear. Closer investigation found the reaction was caused by nickel in the mobile phone handsets.

In addition, a US study by Brown University tested 22 handsets from popular brands for nickel, and found it in 10 of them.

Dr Lionel Bercovitch, 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."

However the GSM, an organisation representing mobile phone operators, said many phone models are available that do not contain nickel on surfaces.

A representative for the organisation said: "Some manufacturers plan to phase out use of nickel on surfaces across their product range."

He said using a case or handsfree kit would help minimise contact to surfaces that may contain nickel. BAD also advises anyone who develops a rash on their face to seek advice from their doctor.