Children in soaps have a strange habit of disappearing upstairs only to reappear sometime later as a completely different person. The latest is Coronation Street's Tracy Barlow, who's changed her body, but not her morals.

Tracy Barlow is the girl who went upstairs to play records and didn't come down again for nine months. She must have been listening to the longest long-playing record in history.

Nobody in Coronation Street mentioned her absence, behaviour sadly symptomatic of the way children are treated in soaps. Or rather, mistreated, a subject that has been a cause for concern in this column in the past. Two years ago I worried how Sarah Louise Platt had managed to become a schoolgirl mum without any noticeable contact with the opposite sex.

She was, of course, a victim of the storyliners' imagination which exploits soap children ruthlessly for the sake of ratings. Their comings and goings are rarely based on logic or credibility, but more usually on the need to provide an adult character with a plot.

Tracy has already been dubbed "the Street's most troubled teenager" with two broken marriages, a drugs overdose and liver transplant behind her. We shouldn't have been surprised when she jumped into bed with Dev, boss and one night stand of her mother Deirdre, within five minutes of arriving back in Weatherfield.

Neither her manners nor her acting have improved. She's now Tracy Preston, but has left her husband in London while she romps with the men of Weatherfield. Her dangerous liaison with Dev is not only a gift to headliner writers (who claim that Deirdre is DEV-ASTATED) but lights the touch paper under the possibility of the Dev and Deirdre secret leaking out.

Newcomer Kate Ford stepped into Tracy's shoes after the last actress to play her, Dawn Acton, failed an audition to win back the part. The decision was said to have left her "devastated", just like her mum. She'd already displaced two previous Tracys to play the role for eight years until 1996, with a few fleeting appearances since then.

She's had more than her fair share of trouble including being kidnapped, taking a bad Ecstasy tablet and suffering renal failure. Happily, Deirdre's husband Samir volunteered one of his kidneys, shortly before being found unconscious by the canalside after a beating.

Clearly, there's something in the water in the Barlow household because Ken's children make a habit of changing faces. The current Peter Barlow, Chris Gascoine, is the seventh actor in the role. His predecessors included Linus Roache, real life son of William Roache, who plays Ken Barlow.

The shock of his mother's death - she was electrocuted by a hairdryer - sent young Peter to live with his maternal grandparents in Scotland. Every time he came back to see Ken, he had a new head.

His twin, Susan, suffered from similar schizophrenia, being played by four actresses before being killed in a car crash. Short of a Bobby-in-the-shower Dallas dream sequence, no other actress will be required to step into her shoes.

It's odd how simply leaving home results in major physical changes for soap children. Janine Butcher made her first appearance in EastEnders in 1993 with Rebecca Michael in the role. After a spell in Manchester, she returned as Alexia Demetriou. Another trip up North led to her reappearance as Charlie Brooks.

After discovering that the man he called dad, Ian Beale, wasn't his real father, young Steven Beale has gone off to live in Australia. We can be certain that one day he'll arrive back in Albert Square looking completely different, just as Nicky Tilsey did when he returned to Coronation Street from Canada with floppy blond hair and a six-pack stomach.

In Emmerdale, Scott Windsor joined the army in 1995. Young actor Toby Cockerell went off on manoeuvres and returned as someone completely different, a new and improved heart-throb version called Ben Freeman.

Just think if the original Scott Robinson hadn't left Neighbours, we might never have heard of Jason Donovan. When Darius Perkins couldn't cope with the fame of being in the Aussie soap, producers replaced him with young Jason.

Physically, Donovan and Perkins didn't look similar. But that's not a factor in replacing soap children. Neighbours welcomed a variety of Lucy Robinsons, some blonde and some not.

Sometimes performers became too famous for other things away from the screen that producers look elsewhere. Daniella Westbrook and her nose attracted much attention in the press, so when EastEnders' bosses wanted Sam Mitchell to return, they cast another actress in the part.

The EastEnders tradition rules that Walford offspring are tearaways or tarts, or possibly both. Their criminal records are as long as traffic queues on the M25. Martin Fowler has been called the teenager from hell after thieving and getting Sonia pregnant. He's now facing a prison sentence after knocking down and killing Jamie Mitchell with his car. As he was banned from driving, was uninsured and looking at a text message on his mobile phone at the time of the accident, his chances of escaping jail seem slim.

If he's sent down, no matter - there's another Fowler teenager waiting in the wings. Vicki Fowler, last seen as a nine-year-old in 1995, is returning to Walford this month after going off with mum Michelle for a new life in America.

Sixteen-year-old Michelle, you may recall, had little Vicki after a liaison with landlord Dirty Den in the Queen Vic pub. Now Vicki's coming back and, like all soap children, will probably make the same mistakes as her mother. But, if it all gets too much for her, she can always change her head for a new one.

Published: 04/01/2003