The painful skin condition is linked with non-communicable diseases like cardiovascular disease, type 2 diabetes, and mental illness. Effective screening and treatments can improve outcomes, but costs remain a significant barrier.
Screening psoriasis patients for chronic conditions and access to new drugs can improve health outcomes, but cost remains a barrier. Photo: Andrey Popov
Psoriasis is a troubling skin condition that affects 60 million people globally. It causes itchy, crusty, raised plaques covered in scales on the knees, elbow, trunk, and head. The WHO recognised psoriasis as a serious non-communicable disease (NCD) in a 2016 report, highlighting the distress caused by misdiagnosis, inadequate treatment, and stigmatisation.
Crucially, psoriasis is now acknowledged as more than a skin disease, and as a whole-body condition that can raise the risk of other NCDs like cardiovascular disease (CVD), type 2 diabetes, and depression. Screening for NCDs and treatment with powerful biologic drugs can improve health outcomes for the global psoriasis population.
Probing the link between psoriasis and other NCDs
Psoriasis can be painful and disfiguring. An analysis published in the International Journal of Dermatology found that incidence of new cases of psoriasis rose from 92 per 100,000 people in 1990 to 99 per 100,000 in 2017. Global prevalence is estimated at 811 per 100,000 people, and a growing body of research shows that its impact on the body can extend far beyond the skin.
“Psoriasis affects the whole body, and we know that treating the disease early may prevent serious, irreversible consequences.”
“There is growing recognition that psoriasis can have comorbidities, including CVD, high cholesterol, raised blood pressure, depression, inflammatory bowel disease, type 2 diabetes, and psoriatic arthritis,” says Professor Chris Griffiths, consultant dermatologist at King’s College Hospital, London, and co-founder and director of The Global Psoriasis Atlas, which has been gathering data on the prevalence, comorbidities, and economic consequences of psoriasis since 2017.
Worryingly, patients with psoriasis are up to 50% more likely to develop CVD and 27% more likely to have type 2 diabetes. Around 30% of people with psoriasis develop a chronic inflammatory disease of the joints and entheses, where joints and ligaments connect to bone.
A community clinic in Manchester found that even during the early days of psoriasis onset, between one-quarter and one-third of people had high blood pressure, raised cholesterol, or depression, Griffiths says. One in five had joint symptoms severe enough to warrant a referral to a rheumatologist.
However, Griffiths says, many governments and health systems continue to view psoriasis as a cosmetic problem, rather than a serious issue like CVD or diabetes, which impedes treatment of the condition itself as well as diagnosis and treatment of comorbid conditions. “Psoriasis affects the whole body, and we know that treating the disease early may prevent serious, irreversible consequences,” he says.
In many communities, there is scant awareness of the link between psoriasis and other NCDs. Anna McFadyen, a clothing entrepreneur living in London, has had psoriasis and psoriatic arthritis, which affects her nails, since her teenage years. She was shocked to learn that the condition has affected her cardiovascular health.
“I’m not overweight, I exercise and swim regularly, eat healthily, don’t smoke, and don’t have any other risk factors for heart disease, but I found out two years ago that I have thickening of the walls of my carotid artery, which puts me at higher risk of a stroke, and raised levels of lipoprotein A [linked to higher risk for CVD],” says McFadyen, who is a former expert patient on the psoriasis clinical guideline committee of the UK’s National Institute of Health and Care Excellence (NICE), an independent advisory body that advises the NHS on effectiveness of treatments.
“I only discovered this after paying for private blood tests after reading about the increased risk of heart disease and stroke—I wasn’t being screened for CVD routinely. There needs to be more recognition of the comorbidities associated with psoriasis [because] screening and early treatment may be able to prevent some of them.”
The role of inflammation and screening
It is believed that psoriasis and other NCDs share an association with inflammation. “If you have one of the conditions, it will probably make you more prone to the others,” Griffiths says. “It does not necessarily follow that psoriasis drives all these conditions, although that is one school of thought. These patients have a lot of inflammation in various organs, which may be due to inherited susceptibility genes—but there’s no doubt there is an association.”
Given the substantial disease burden, raising awareness on the link between psoriasis and other NCDs, and screening for these conditions could have a huge impact on health systems globally.
“We may hypothesise that early and effective treatment of psoriasis would restore the dysfunction and eventually prevent the future risk of [heart attack] and heart failure.”
“We should be screening patients with psoriasis for these other conditions,” Griffiths says. “Screening for these risk factors early means they can be controlled with therapies and lifestyle changes, such as losing weight or lowering cholesterol.”
Research published in the Journal of Investigative Dermatology last year by scientists at the University of Padua found 32% of psoriasis patients had reduced blood flow in their small blood vessels, which has been shown to predict poor cardiovascular outcomes, even though they did not have any symptoms or blocked arteries.
Lead investigator Dr Stefano Piaserico says there had previously been limited research on the specific mechanisms underlying this increased risk. “We should diagnose and actively search for [reduced blood flow in the small blood vessels] in patients with psoriasis, as this population is at particularly high risk,” he says.
“We may hypothesise that early and effective treatment of psoriasis would restore the dysfunction and eventually prevent the future risk of [heart attack] and heart failure.”
Piaserico says preliminary studies show that reduced blood flow in the small blood vessels, or ‘coronary microvascular dysfunction’, is restored after treatment with biologics, a new type of medicine, but studies are needed to confirm whether this helps reduce heart attack and stroke.
Flow-on effects for mental health and wellbeing
Greater awareness of the link between psoriasis and other NCDs and the use of screening programmes can improve mental health outcomes.
One in 10 people with psoriasis is also diagnosed with clinical depression, and nearly 48% experience anxiety. The inflammation likely linked to poor cardiovascular health is also associated with mental health conditions, and there are psychological factors at play as well.
People with psoriasis often report feelings of being caught in a vicious cycle—psoriasis can cause depression and anxiety, which can, in turn, worsen psoriasis.
Psoriasis causes itchy, crusty, raised plaques covered in scales on parts of the body like the elbow and there are strong links with mental health conditions. Photo: Dave Bolton
Stigmatising attitudes towards people with psoriasis persist and can have a significant impact on mental health. A 2019 study that surveyed American laypeople and medical students found 39% would not want to shake hands with a person with psoriasis, while 27% thought psoriasis was contagious. People with psoriasis say they are sometimes asked to leave public swimming pools or discriminated against in the workplace.
Silvia Fernandez Barrio, a board member of the International Federation of Psoriasis Associations (IFPA) and founder and president of the Asociación Civil para el Enfermo de Psoriasis (AEPSO) in Argentina, says: “Skin diseases such as psoriasis have been stigmatised since Biblical times. Many of the people who were put in leper colonies didn’t have leprosy at all, but psoriasis.”
In Argentina, a 2018 AEPSO survey of quality of life for patients with psoriasis serious enough to require biologic therapies found 16% reported having active suicidal ideation. Four in 10 rejected social invitations due to their skin condition and eight in 10 said they changed the way they dressed because of psoriasis.
“In Argentina we have done a lot of work with patients and the public on dispelling myths about psoriasis being contagious or linked to poor hygiene,” Fernandez Barrio says. “I say it is like having your arm in plaster—people will see it and ask what is wrong with you and what caused it, and it is the same with psoriasis.
“The way to respond is to say that you produce new skin within two to three days [rather than the usual] 28 days. It is a non-communicable disease and that is the only difference between [you] and other people.”
People with psoriasis can also have low self-esteem connected to their appearance and this can lead to anxiety and depression, says Dr Hoseah Waweru, a dermatologist, who is chairperson of the Psoriasis Association of Kenya and president of the IFPA. “There are cases of suicide and attempted suicide in people with severe psoriasis symptoms—it can really affect mood and mental health,” he says.
“People with psoriasis can face loss of employment and there is a wrong perception that they are somehow unclean.”
Waweru says attitudes are changing in Kenya thanks to public information campaigns. “People with psoriasis now feel they can go out and use public transport. If they are asked about their skin symptoms, they can explain what it is and what causes it,” he says.
High costs preventing access to biologics
Caused by the speeding up of skin cell renewal and mainly driven by genetics, psoriasis has been traditionally hard to treat with topical creams, light therapies, and systemic treatments that target the entire body, such as the drug methotrexate.
Treatment of psoriasis has been transformed by biologics, a newer and stronger type of medicine that works by blocking reactions in the body that cause psoriasis and its symptoms. Administered by injection or IV infusion, biologics can target only the part of the immune system that is overactive because of psoriasis. There is decreased risk of liver and kidney problems compared with other medicines. For many people with psoriasis, taking a biologic is life-changing.
The high cost of biologics has been a barrier to access in many countries since the drugs became available at the beginning of the century. In the UK, only people with severe psoriasis have been able to get biologics through the publicly funded NHS. Biosimilar drugs, which are structurally similar and significantly cheaper, are now available.
Campaigners in Argentina were successful in getting biologics approved for use by health services for free, but Fernandez Barrio says not all places in the country have equal access to it. “In some areas patients are given a different biosimilar every month, which is not acceptable,” she says
"We are living in a time of crisis and we don’t know how this is going to affect access to treatments, but there is a chance we could be going backwards."
A 2018 online survey by AEPSO of 1,469 patients with psoriasis found 20% had received some type of biological therapy, but 33% said they had trouble accessing biologic treatments. It is a similar situation elsewhere in Latin America. A study of 1,424 people with moderate to severe psoriasis found only 37% in Brazil and 27% in Chile had received biologic treatments.
Fernandez Barrio says Argentina’s new government is also making austerity cuts to all public spending, which may affect access to biologics. “Inflation is 25% and 54% of the population is living in poverty. We are living in a time of crisis and we don’t know how this is going to affect access to treatments, but there is a chance we could be going backwards,” she says.
In Kenya, Waweru says, biologics were included on the essential drug list with assistance from the WHO. “But most people are still unable to afford them, so cost is the other issue—prices must come down,” he says.
Crucially, he says, improving global access to biologics has the potential to improve outcomes for people with psoriasis and other NCDs.
“Access to treatments is the biggest issue in Kenya and globally,” Waweru says. “We are talking to government representatives, payers, and insurers about how serious a disease psoriasis can be and how biologics can help, as well as the benefits of biosimilars and other systemic treatments such as methotrexate.
“Globally we have to convince governments and insurers that psoriasis, although a serious condition in its own right, is also a red flag for cardiovascular disease and other NCDs.”
Griffiths agrees: “Only a fraction of the people with psoriasis are getting access to these treatments currently. This is why we are collecting the Global Psoriasis Atlas data, so we can make the case for the societal, economic, and personal consequences of psoriasis and enable people with psoriasis to have access to the best available care.”