"I like the way they look," she says. "I don't consider myself to be a particularly pretty or outstanding person, but with a few piercings I can look different and therefore I can make myself outstanding. I imagine I'll have them when I'm 61." It is doubtful whether Zara Phillips, Princess Anne's teenage daughter, who sports a metal stud in her tongue, will keep hers into old age, but both girls are merely conforming with their peers who are happily adorning their tongues, lips, eyebrows and navels. Many practitioners have noticed a rapid increase since last Christmas when "Scary Spice", Mel B, had her tongue pierced.
"When I first started piercing 14 years ago it was older people having nipple or genital piercings to add a bit of spice to their lives," says Philip Barry, a Bristol-based piercer, and chair of the European Professional Piercers Association. "Now you get a lot of young people, even school children, who want their navels or tongues pierced."
Is having your tongue, navel or nipple any more dangerous than having your ears pierced? Is there any truth in rumours that you can lose your taste buds, develop tongue paralysis, injure the muscles around the stomach and develop abscesses up your nostrils?
If carried out by trained piercers in hygienic studios, and followed up by meticulous after-care, piercing is remarkably safe. The main danger comes from untrained piercers working in unhygienic premises, and from poor after-care.
Of the thousands of piercers in Britain, only 450 are registered with the European Professional Piercers Association, which monitors standards of training and hygiene, and a handful belong to the US Association of Professional Piercers. Most piercers are registered with their local councils, but hundreds - the cowboys of the trade - are not, and have little or no training.
Anyone, of any age, can be pierced. According to the Department of Health, when it comes to body piercing, the courts have ruled that parental rights yield to a child's right to make his or her own decision. Most reputable studios refuse to pierce anyone under 16 without parental consent.
At Cold Steel in Camden, north London, which pierces hundreds of people a week, no one under 18 is pierced without parental consent. "We just don't do it," says Paul King, a master piercer. "People put no thought into their piercings. They just get pierced at their closest studio, rather than shopping around for the best and most reputable one."
Professor Norman Noah, an epidemiologist at the London School of Hygiene and Tropical Medicine, and the Communicable Disease Surveillance Centre, who is Britain's "piercing tsar", has drawn up guidelines to which tattooists, acupuncturists and now piercers should adhere. He approves new ear-piercing guns and says that equipment is now so safe that danger from blood-borne viruses such as HIV, Hepatitis B and C is virtually non-existent.
Leeds City Council last year banned the use of the piercing-gun on any part of the body other than the ears, when a number of people developed infections after having their belly buttons pierced with ear-piercing guns.
Inexperienced "cowboy" piercers may also thrust in jewellery too small for a fresh wound, with the result that the skin swells around it, causing infection. After piercing, the tongue swells up to three times its normal size and, if the bar-bell is too short, it can cause infection. When the swelling has gone down, the bar-bell can be changed to a shorter one.
Piercing is painless - you just feel a crack when you go through the muscle, according to Kirsty Boyd, manager of the Leeds Piercing Company. "As soon as the anaesthetic wears off, in about an hour, then the pain will come through. The tongue will feel uncomfortable for three to four days and the main swelling will go down in a week or two. It's very difficult to eat and you have to be on liquidised food."
But once the wound is fully healed, the ball of the bar-bell can crack your teeth, as Dr Geoff Craig, an oral pathologist at the Sheffield Dental School explains. "There's a tremendous force applied when you bite. If you are eating and bite down on something, not realising your stud is there as well, you can break a tooth."
Last year, the British Dental journal reported the case of a 25-year- old woman admitted to hospital after her tongue had been pierced. Antibiotics failed to clear up the infection and the bar-bell was surgically removed. She later collapsed with Ludwig's angina, a rare inflammation of the subcutaneous tissue below the chin, tongue and roof of the mouth.
"There may be no evidence that having your tongue pierced causes a loss of taste or paralysis, but I would find it find it difficult to condone the practice," says Dr Craig. "Any swelling can threaten your breathing. The potential for infection is there all the time."
So why do it? Martin Skinner, a social psychologist at the University of Warwick, explains: "It's another way of rebelling and showing you're unique. Each generation has to do something a bit more to startle an older generation, and to establish themselves as different. Who knows what people will have to do in 20 years' time? There's a continuum of body piercing, from ears, through the nose, which is now pretty acceptable, and the tongue, which is becoming more so. We're not quite at the clitoris, but we're getting there."
Contact The British Association of Aesthetic Plastic Surgeons, c/o The Royal College of Surgeons, 35-43 Lincoln's Inn Fields, London WC2A 3PN; European Professional Piercers Association, 201 Two Mile Hill Road, Kingswood, Bristol BS15 1AZ (01179 603923); The Association of Professional Piercers, P0 Box 16044, London NW1 8ZD