It’s an agonising and disfiguring skin condition that plagues one in every 100 Britons – yet very few have ever heard of hidradenitis suppurativa (HS).
A chronic inflammatory disease, it causes painful, boil-like lumps to form deep under the skin in areas such as the armpits and groin.
Occurring when hair follicles are blocked, flare-ups can resemble ingrown hairs. But left untreated, HS can cause weeping sores curable only by surgically removing the affected area of skin.
For decades, treatment has been limited to antibiotics, antibacterial washes and pain relief. But for many with severe cases of HS, this cannot fully clear up outbreaks or prevent future ones.
Now experts say research suggests a new range of drugs could target the underlying cause of the condition – inflammation.
Called JAK inhibitors, these medications are already used to treat inflammatory conditions from rheumatoid arthritis to eczema. But a growing body of evidence has found they could also be a new therapy for HS, by blocking the inflammatory signals that drive the disease at the cellular level.
While the drugs can’t reverse the severe skin damage of advanced HS, they could be ‘a gamechanger’ for early or milder cases, says Dr Abirami Pararajasingam, consultant dermatologist and British Skin Foundation spokesman.
She says the US is ‘proactive’ about giving patients these drugs as they have fewer restrictions about intervening.
Laurelle-Maria Sterling, 32, has lived with HS since her teens – a drug called adalimumab greatly reduced the level of inflammation for her
A chronic inflammatory disease, HS causes painful, boil-like lumps to form deep under the skin in areas such as the armpits and groin (picture posed by model without HS)
But she adds: ‘In the UK, there are issues with pricing that mean patients can’t access them. Not only is HS painful and, for many, embarrassing, chronic inflammation is also a risk factor for other long-term health issues – from heart disease to stroke. We need to be intervening earlier.’
Once thought to be rare, more than 700,000 Britons are now estimated to have HS. One of the most famous sufferers was political theorist Karl Marx.
Caused by an overactive immune system which triggers an abnormal inflammatory response when hair follicles become blocked and infected, it can vary widely in severity.
For some, flare-ups resemble small blackheads, boils or under-the-skin lumps that go on their own. For others, lesions become open wounds that take years to heal and cause extensive scarring. Women are more likely to be affected than men, with most experiencing symptoms in their early to late teens.
As the condition often appears to mimic other common ailments and lacks a single definitive lab test, HS can take up to ten years to diagnose in the UK.
As a result, says Dr Beibei Du-Harpur, clinical lecturer in dermatology at King’s College London, many patients live for years without understanding what is going on.
‘If HS is diagnosed and treated early, much of the worst damage can be avoided,’ she says. ‘[But] people are just sitting at home coping as that damage is occurring because they don’t understand what’s happening. This lack of awareness is also a huge issue among clinicians.’
Experts still aren’t sure exactly what causes the condition, but it’s estimated that one in three cases is genetic. Other factors are being overweight and smoking.
Nicotine and other chemicals in tobacco smoke bind to receptors in skin cells, encouraging abnormal skin thickening which blocks hair follicles. Being overweight can see pro-inflammatory chemicals released by excess fat tissue, creating a low-grade inflammation that can trigger or worsen HS.
One of the most famous sufferers of HS was Karl Marx, who lived in the 19th century
Many patients live for years without understanding what is going on, says Dr Beibei Du-Harpur, clinical lecturer in dermatology at King’s College London
Extra body weight can also create deeper skin folds, under which HS eruptions can occur. But not all sufferers are smokers or overweight. ‘Some people are simply more prone to HS because of their hair follicle and oil gland structure,’ says Dr Du-Harpur.
Early cases of HS are usually treated with courses of antibiotics and prescription creams or gels. But research has led to huge advancements now beginning to trickle down to patients in the UK.
Called biologics, this new range of drugs target and block specific immune system proteins that drive painful inflammation and tissue damage, reducing flare-ups and preventing future outbreaks.
For many, the drugs have already been life-changing. Laurelle-Maria Sterling, 32, has lived with HS since her teens. Diagnosed at 20, when she was regularly in and out of hospital, she was prescribed course after course of antibiotics.
‘None of them got rid of the HS,’ she says. ‘My only option was surgery – great for pain relief, as the pain from healing is better than the pain from the condition – but it didn’t stop flare-ups in other areas.’
Four years ago she was put on a drug called adalimumab, also used to treat rheumatoid arthritis and psoriasis. She says: ‘It calmed down the level of inflammation. I still get occasional flare-ups but they no longer become as severe.’
In the US, adalimumab and JAK inhibitors are already used to treat milder cases of HS. A study published in Nature found JAK inhibitor povorcitinib cut inflammatory nodules and abscesses in HS patients by more than 50 per cent.
The ‘promising’ JAK inhibitor drugs should be rolled out by the NHS for HS patients in the next year or two, says Dr Du-Harpur.
