Standing at her shop counter, pharmacist Rosie Beaton was overwhelmed by a throbbing pain in one of her toes.
'I was used to aching feet from standing all day every day, but this pain was something off the scale,' says Rosie, 35, who lives in Glasgow with her husband Drew, 39, an accountant at the University of Glasgow.
'I had to apply ice packs to my foot in my breaks three times a day, and after a few days it was so swollen I couldn't get my shoe on - I had to wear trainers.'
The pain had started after Rosie bumped her toe on a chair twice in the space of a week back in 2010.
'I had big red lumps on the front of my right foot and the side of my ankle, but I just soldiered on as I thought it would eventually die down,' recalls Rosie.
She eventually visited her GP, who said she had a soft tissue injury and prescribed a painkiller. But this made no difference and the pain spread to Rosie's hip.
'My left hand was also very weak and painful. I had to use two hands to lift the handbrake on the car,' she recalls. 'I started to think my hip and hand problems might be related to my foot. I wondered if it might be arthritis, as my mum had osteoarthritis in her 50s.'
Rosie's suspicion was right - after two more painful months, her GP sent her for an X-ray, which showed erosion in one of the joints in her foot.
But she was taken aback when her doctor suggested it might be linked to the small patch of scaly red skin on her elbow. 'I'd had psoriasis on my arm for years, and just controlled it with creams,' she says.
'I couldn't think why it was relevant. Then my GP said he thought I had psoriatic arthritis - which I'd never heard of.'
An estimated 1.8 million people are affected by psoriasis, a condition causing itchy, flaky, red plaques on the skin. But few are aware that between 15 and 30 per cent of them will develop psoriatic arthritis - severe pain and inflammation around the joints, similar to rheumatoid arthritis.
It can affect the fingers and toes, neck, lower back, knees and ankles and in severe cases can destroy joints. And that's not the only potential complication.
Dr Justine Hextall, a consultant dermatologist at the Western Sussex Hospital NHS Trust, says: 'Psoriasis is far more than just a scaly skin condition. Often patients don't realise that it can affect the whole body.
'As well as psoriatic arthritis, patients are also at increased risk of heart disease, stroke and type 2 diabetes. We think this is mainly because it can create widespread inflammation in the body, although we don't know the exact mechanisms involved.'
Scientists still don't know for sure why psoriasis can lead to arthritis.
With psoriasis, it's thought that the immune system over-reacts and produces inflammatory chemicals, leading to skin cells shedding and growing too quickly. The extra skin cells build up to form raised plaques on the skin.
Rheumatoid arthritis, on the other hand, occurs when the immune system mistakenly attacks body tissue, leading to inflammation around the joints. The triggers for psoriatic arthritis are thought to include a mixture of genes - 40 per cent of sufferers have a relative with the condition - and environmental triggers including injury, as happened with Rosie, infection and stress.
The problem is that psoriatic arthritis is often missed by doctors. That's because some patients either have no psoriasis skin patches at all or they are very mild - or they get psoriatic arthritis before they develop psoriasis on their skin. Some patients never get the skin symptoms at all.
So by the time patients are diagnosed their joints may already be badly damaged.
'Patients usually haven't heard of psoriatic arthritis yet it can be just as serious and disabling as rheumatoid arthritis,' says Dr Stefan Siebert, a senior lecturer in rheumatology at the University of Glasgow.
'Some dermatologists and GPs don't make the link or pick it up either - there is a large undiagnosed group of patients out there.'
The condition can also be misdiagnosed as other types of arthritis, he adds. 'This means patients can get the wrong or inadequate treatment and suffer joint deformity.'
Although the symptoms of psoriatic arthritis vary, Dr Siebert says there are certain features that should ring alarm bells with doctors.
These include patients with psoriasis who develop joint pain, swelling or stiffness, recurrent Achilles tendon problems, heel pain caused by inflammation of the plantar fascia ligament ('plantar fasciitis') and tennis elbow - pain around the outside of the elbow caused by overusing muscles.
'This is because in psoriatic arthritis the arthritis is not limited to joints but also affects tendons,' explains Dr Siebert.
'People with psoriatic arthritis are also more likely to have other problems including high blood pressure, diabetes, obesity and fatty liver disease. The relationship between these problems is still unclear and an area of active research,' he adds.
Psoriatic arthritis is more difficult to diagnose than rheumatoid arthritis. 'It is diagnosed by taking a careful history and eliminating other types of arthritis such as rheumatoid and osteoarthritis,' explains Dr Siebert. 'Although blood tests can be helpful, at least half of all people with psoriatic arthritis have normal blood tests.'
He says it's vital to raise awareness of the condition. 'Doctors should definitely be asking patients with joint pain if they have ever had psoriasis and those with psoriasis if they have joint pain. Early diagnosis and treatment with drugs is important to prevent future joint damage, as psoriatic arthritis like rheumatoid arthritis generally gets worse over time.'
Her doctor suggested it might be linked to the small patch of scaly red skin on her elbow
Once properly diagnosed, psoriatic arthritis and its symptoms can be treated with common anti-inflammatory medications. Disease modifying anti rheumatic drugs (DMARDs) such as methotrexate can help by suppressing the joint inflammation.
If those don't work then a newer form of DMARDS, called biologics, that target proteins involved in inflammation, may be given either as an infusion or injection.
The newest treatment on the market for psoriatic arthritis is an injection called Stelara (ustekinumab), which targets a different protein implicated in psoriasis and psoriatic arthritis.
However, although this been approved for use in Scotland, the National Institute for Health and Care Excellence (NICE) has not approved it in England.
Yet all of these treatments work best the sooner they are started and Carla Renton, spokeswoman for the Psoriasis Association charity, says members report long delays in getting a diagnosis of psoriatic arthritis. 'Part of the problem is that the symptoms can be missed or mistaken for other conditions including gout, inflammatory back pain, general aches and pains, and rheumatoid arthritis.'
She adds that people with psoriasis often get stuck on repeat prescriptions and don't get reviewed.
This lack of follow-up care fits with Rosie's experience. 'I hadn't seen my GP in years about my psoriasis, because it was so mild I was put on repeat prescriptions for creams,' she says. 'If I'd had an annual review, my psoriatic arthritis may have been picked up earlier and my joint damage prevented.'
Following diagnosis, Rosie was treated with methotrexate and her symptoms are now better controlled. Recently though she's had an MRI scan that suggests she may now have long-term damage to her spine.
'Luckily, I haven't ended up on crutches or in a wheelchair but I know others with the condition who have, so I worry about my future,' she says. 'I already feel like a 70-year-old some days.
'I'm watching my diet and trying to keep fit because having psoriasis means I'm at higher risk of heart disease and diabetes, too.'
Rosie believes anyone with psoriasis should be asked if they also have joint pain. 'It was never mentioned to me - but all the time a skin condition was attacking my joints.'
Source: dailymail.co.uk
