Imagine having an illness that makes your face erupt in a rash, your hair fall out and your joints so sore you cannot hold a mug of tea. While the drugs prescribed to treat it might ease the symptoms, the relief is temporary and short-lived.

One of the main treatments – oral steroids – will eventually make things worse, causing significant weight gain and raising your risk of broken bones, heart disease and strokes.

For an estimated 15,000 people in the UK living with a condition called lupus, this is an everyday reality. As if the illness itself was not bad enough, the remedy of high doses of oral steroids is just as unappealing.

For decades, these drugs, and their considerable side effects, were the only significant weapon doctors had to combat this crippling and incurable condition. There are newer drugs that do help, but often are of limited benefit.

Pop singer and lupus sufferer Seal with his ex-wife, supermodel Heidi Klum, in 2011

But late last year, researchers discovered what they believe to be the biggest breakthrough in lupus treatment in decades.

Remarkably, the drug, called anifrolumab, appears able to completely banish symptoms, such as the severe rash on the face and painful, swollen joints, and means patients can slash their use of dreaded steroids, or even come off them altogether.

Instead, they need only attend hospital once a month for a 30-minute injection of the liquid drug into a vein in the arm.

Scientists are even reported to be working on a DIY injection kit that would allow patients to treat themselves at home.

British doctors trialling the ground-breaking new drug say it could revolutionise treatment of the most severe form of the disease - systemic lupus erythematosus, or SLE.

‘It is the first ever medicine specifically developed for the treatment of lupus,’ says Dr Ed Vital from the Leeds Institute for Rheumatic and Musculoskeletal Medicine. ‘The patients who benefit most are those with severe facial rash and sore joints who fail to respond to all other treatments. For many, the rash is one of the worst symptoms.’

Lupus develops when the body’s immune system goes haywire and attacks healthy cells and tissue. Often, this is as a result of something fairly innocuous, like a mild viral infection that sufferers never even knew they had. As a result, the bloodstream is flooded with interferons, a type of protein which normally patrols the body looking for invading viruses to attack.

In lupus, the production of interferons is over-stimulated so much that the proteins cause damage to the skin, joints and major organs.

The disease gets its name from the Latin for ‘wolf’ because the facial lesions it causes have been likened to a wolf’s bite. In rare cases, rashes can be so severe they lead to deep, pitted scars on the cheeks. The condition also makes patients so sensitive to sunlight that even a few minutes outdoors on a hot day can make the skin blister, joints become inflamed and internal organs swell – increasing the risk of organ failure.

Dr Vital said: ‘It can leave pitted scars on the face and that’s something young women – who are often those affected – really don’t want.’

But men can get it too. The award-winning singer Seal, best known for his hit Kiss From A Rose and his marriage to supermodel Heidi Klum, developed a form of the disease in his early 20s.

‘It can leave pitted scars on the face and that’s something young women – who are often those affected – really don’t want,' Dr Vital said

Evidence of the 56-year-old’s condition can be seen on his face, with telltale scars marking his cheeks.

The new drug anifrolumab makes the unsightly sores vanish before scarring occurs. It works by binding to receptors on the surface of cells in the body – the same receptors that interferon proteins normally stick to.

This stops interferon from getting into cells in the skin, joints and organs and triggering the agonising symptoms.

It’s not clear yet whether patients will have to remain on the drug for the rest of their lives.

Currently, the drug is restricted to patients taking part in clinical trials in the north of England.

Astra Zeneca, the company which developed anifrolumab, says it hopes it will be available for NHS patients in the UK in the next two to three years.

One sufferer whose life has already been transformed is 45-year-old Sam Coates from Leeds. Until recently, Sam lived like a virtual recluse, spending much of her time at home for fear of showing others the red, angry rashes that covered her face.

The mother-of-two was diagnosed with lupus aged just 25 after noticing a red rash across her cheeks.

Her GP diagnosed rosacea – a common skin complaint in adult men and women – and gave her a cream that just made it worse.

Soon she noticed her knees, fingers and wrists hurt all the time.

‘I couldn’t even pick up a cup of tea and felt so tired I would fall asleep in the day,’ she says.

‘I must have visited my GP 30 times in just eight months before I finally got referred to a rheumatologist, who carried out blood tests and diagnosed lupus. I’d never even heard of it.’

Sam was put on a high dose of oral steroids and, within weeks, began to feel better.

The joint pain subsided, her hands worked properly again and she began to regain her energy. But over the following years, she needed increasingly higher doses of the drugs just to take the edge off the symptoms.

Sam also gained seven stone over the course of her illness – a common side effect of steroids.

‘My weight got so bad I started to develop early-onset osteoarthritis. And if I went out in the sun even for a few minutes my face, chest, back and legs would blister.’

So when, in 2017 the opportunity arose to take part in a groundbreaking new trial, Sam grabbed it.

She began visiting her local hospital monthly to have the new drug injected into a vein in her arm.

After just three or four treatments she noticed a significant improvement in her health. ‘The rash subsided, my joints felt less stiff and painful and my weight began to drop. My skin has now been completely clear for well over a year – no hint of a rash.

‘I’ve been able to socialise more, and enjoy hot summer days out at the seaside with my family.

‘Before I was put on this new drug, I couldn’t even hold a pen.’

Sam has cut her daily dose of steroids from 25mg to just 5mg.

‘And I’ve lost nearly three and a half stone,’ she says. ‘This drug has completely changed my life.’

Dr Vital says many more like Sam could benefit.

‘She has had such a terrible time with this disease.

‘But the new drug has made a huge difference to her life.’