Stars including Benedict Cumberbatch, Sienna Miller and Damian Lewis have joined forces to film themselves performing difficult tongue-twisters in support of a 12-year-old girl whose skin blisters at the slightest touch.

Sohana Collins from London suffers from an incredibly rare genetic disorder called epidermolysis bullosa (EB). If Sohana’s skin is touched, even lightly, it reacts as if she’s been burned.

Sohana Collins suffers from an incredibly rare skin condition

Her hands are so fragile she has to wear gloves, and all her food must be liquidised as her mouth and oesophagus are also prone to blistering.

Her mum, Sharmila Nikapota, 45, contacted Homeland actor Damien Lewis and, after learning about Sohana, he agreed to become patron of a charity in her name - The Sohana Research Fund.

As the name of her condition is quite the tongue-twister in itself, Damien had the idea to film himself stumbling over another awkward tongue-twister before nominating Sherlock star Benedict Cumberbatch to do the same.

In turn, Benedict nominated actress and model Sienna Miller, and since then BBC presenter Mishal Husain, Damien Lewis’ wife actress Helen McCrory and Emma Watson have also thrown their weight behind the campaign.

Stars including Homeland's Damien Lewis have backed the campaign

Sharmila hopes the campaign will be as big as the ice bucket challenge, which dominated social media timelines last summer and raised over $98 million for the Amyotrophic Lateral Sclerosis Association.

“When Sohana was born in 2002, there was very little prospect of an effective treatment let alone cure, but breakthroughs in research underpin the significant hope that this is no longer the case,” she said.

“It is critical that funding is achieved for key projects that will harness this research optimism.”

She added: “Delays in funding the research will delay results and compound the suffering of all children alive with the condition today.

“EB is considered a rare condition and as such does not attract government funding. This means that all research is private donor and private company led. With the real hope of safe effective treatments and possibly a cure within sight, it would be travesty not to be able to undertake the research necessary.

“Children with burns would not and should not be ignored. Nor should those who suffer EB. This is a chance to make a difference to an incredibly painful, disfiguring and ultimately fatal condition. As parents it is difficult to smile and remain positive.”

Sohana poses with actress Emma Watson

She told of how her daughter’s skin was incredibly tender, explaining how she has to have her food liquidised because swallowing is so painful.

“She is so brave,” Sharmila, 45, said. “It’s very painful for her and having her dressings changed is terrible. But despite this she goes to school and is very bright. She works hard and smiles. She’s very accepting.”

You can find out more and support Sohanna by visiting her Just Giving page.