No, I don't do drugs: Peaches Geldof blames psoriasis for causing marks on her arm

Peaches Geldof has hit back against claims that drug use is the reason behind her dramatic weight loss.

The daughter of Bob Geldof was spotted at the Vivienne Westwood men's store in central London for Vogue's Fashion Night Out event on Wednesday night looking worryingly thin and with marks on her arms.

The 22-year-old wore a flimsy metallic Vivienne Westwood dress to the fashion event, which hung off her tiny frame and showed her protruding collarbone.

Gaunt: Peaches Geldof at the Vivienne Westwood store for Vogue's Fashion's Night Out Party

Peaches has now insisted that she has not been taking heroin and told the Sunday Mirror: 'I don't do drugs.'

The part time model was also sporting some strange bruises on her arms close to her veins fueling speculation that she has been using drugs.

She said to the newspaper: 'The marks on my arms have been there since childhood. Check any picture - it's caused by a skin condition called psoriasis.'

No drugs: Peaches says her weight loss is down to healthy eating and flu

Three years ago the star reportedly suffered an accidental heroin overdose, the same drug her mother Paula Yates died from in 2000.

She has insisted that her weight loss has been 'healthy' and attributed the dramatic difference to her figure was a result of cutting out junk food.

She told the Evening Standard: 'I've lost weight. I've had avian flu.'

The socialite went on to defend her new lifestyle on Twitter, insisting she was perfectly healthy.

Spinning the wheels: Peaches Geldof gets behind the decks at the Vivienne Westwood men's store

She said: 'To those telling me I look skinny and to eat something, I can assure you I've just cut out eating c**p. I still eat like a horse, guys!

Peaches also defended her reputation against reports that the police and ambulances were called out to her North London home on Tuesday night for a man suffering breathing problems.

She said: 'As for the 30-year-old man OD-ing in my house, it's not true and my lawyers are dealing with this. It's about time people stopped thinking the worst of me.'

Unrecognisable: Onlookers said they didn't realise at first glance that it was Peaches

Metropolitan Police said: 'When police arrived, London Ambulance Service had already given medical treatment and the man was taken to hospital.

'No offences were disclosed and no further action is being taken.'

Dropping pounds: A plumper Peaches DJ's at Maya in London in 2008