We would say to people to proceed with extreme caution and if they think they are slightly allergic they should not go for one at all

A spokeswoman for the British Allergy Foundation

But people getting their tattoos in back street shops and some developing countries, where the controls are less strict, are at greater risk.

Allergic reactions

Henna tattoos are a long established practise in India, where it is called mehendi, Morocco and Fiji.

And the tattoos have recently become more popular in the UK, particularly after popstar Madonna had her hands elaborately decorated for the video for her song Frozen.

Dr Bjorn Hausen, of the Dermatological Centre, in Buxtehude, Germany, said his research showed that henna containing PPD could cause contact dermatitis and made the skin swollen, red and itchy.

He added it could even stop people taking jobs in certain industries where they might come into contact with the chemical.

Dr Hausen said: "It is possible that the mark from the tattoo will remain for several months, which is of course socially quite uncomfortable if it concerns parts of the body which are very visible such as the hands or the fingers.

"But above all, these tattoos can cause a hypersensitivity to PPD.

"Because the chemical is used in several industrial processes, that means adolescents who are affected will be unable to enter a number of professions."

Skin sensitivity

The British Allergy Foundation warned anyone with sensitive skin to avoid the tattoos.

A spokeswoman said: "With the growing rate of allergies that are affecting people we would say to people to proceed with extreme caution and if they think they are slightly allergic they should not go for one at all."

Dr Hausen's findings appear in Deutsches Arzteblatt, the Journal of the German Medical Association and New Scientist.