Fashionable temporary henna tattoos could seriously damage your health, a leading Bradford dermatologist has warned.

The fashion accessory, based on the traditional mehndi patterns used in the Middle East and Asia, has been sported by celebrities such as Madonna.

They have been found to contain a banned chemical which can cause lasting damage to wearers.

The chemical paraphenylenediaminem, or PPD, is banned in the European Union. It leaves most people with lifelong allergies to items such as sunscreen, local anaesthetic and eye shadow.

Consultant dermatologist at Bradford Hospitals NHS Trust, Dr Derek Barker, said the reaction was rare but very dangerous and warned users to take precautions.

"Whereas henna itself is a natural product and causes no problems, we are finding that the tattoos contain a chemical called PPD which can cause problems. Although a reaction is not very common, when it does happen they are severe. It can be a very painful reaction."

He said black tattoos were to be avoided as they were more likely to contain the chemical.

"Given the current fashion, it is advisable to make the warning. Treat the tattoos as you would do hair dye and do a skin patch test 24 hours before or use only natural henna."

Neta Patel, 25, of Coll Place, Odsal, pictured, said she used tattoos and had not experienced any problems until trying the henna one.

The customer services officer, who is also a part-time dancer, said: "I have tried lots of them, in different colours and ones with glitter which are popular at the moment.

"I had not used the henna tattoo before, and although it was fine for a little while I soon realised that my skin was peeling.

"I got a burning sensation and had to wash it off straightaway.

"I was a bit shocked, really. The packet says the tattoos are 100 per cent safe so the manufacturers must be aware of the dangers. I'm just glad I managed to wash mine off before it got really bad.

"It's a real shame though because it looks really good and they are less hassle than proper mehndi which stains everything and lasts for too long."

Vaseem Kader, of Bombay Stores, which stocks temporary tattoos, said customers had not had any problems with them.

He said: "The temporary ones are very popular with western people. They have been made popular by celebrities like Madonna and they are favoured because they wash off straightaway instead of going pale and lasting ages."