A commonly-used cancer drug can make patients' fingerprints disappear, potentially causing problems for foreign travel, a doctor warns.

The patient's doctor, Eng-Huat Tan, from Singapore, advised all travellers to the US being treated with the drug capecitabine to carry a doctor's note.

Although the drug is commonly used to treat a range of cancers, it can cause chronic inflammation of the palms or soles of the feet, leading to peeling, bleeding or blistering of the skin.

Over time this can lead to the loss of fingerprints.

Dr Tan said: "Patients taking long-term capecitabine may have problems with regards to fingerprint identification when they enter US ports or other countries that require fingerprint identification and should be warned about this.