• Posted April 18, 2025

Psoriatic Arthritis Diagnoses Are Lagging, Patients Undertreated

It’s taking too long for people with psoriatic arthritis to be diagnosed and treated, a new study argues.

Visible signs of psoriatic arthritis appear months and even years before a person develops the full-blown inflammatory joint disease, British researchers reported in the Annals of the Rheumatic Diseases.

Unfortunately, delays in diagnosis mean that many patients will suffer irreparable damage to their joints before treatment starts, they said.

“Delays to diagnosis of just six months can result in worse physical function for a patient in ten years’ time, so diagnosing and treating the disease early, to prevent structural damage and preserve function, is vitally important,” senior investigator Dr. William Tillett said in a news release. He's a consultant rheumatologist with the Royal National Hospital for Rheumatic Diseases in Bath, U.K.

“This disease can have a massive impact on people’s lives and make it difficult for them to work and manage regular daily activities,” he added.

Psoriatic arthritis occurs when the immune system becomes overactive, causing inflammation in the joints.

As the name would imply, this type of arthritis is linked to the autoimmune skin disorder psoriasis. More than 8 million people in the U.S. have psoriasis, and of those about 30% also develop psoriatic arthritis, according to the National Psoriasis Foundation.

For the new study, researchers compared 2,120 people diagnosed with psoriatic arthritis with patients who have rheumatoid arthritis.

People with psoriatic arthritis suffered longer with symptoms before they were referred to a doctor compared to those with rheumatoid arthritis, results showed.

Nearly 44% of psoriatic arthritis patients had symptoms for six months to five years before being referred to a doctor, compared with 32% of people with rheumatoid arthritis, researchers report.

Once referred, it also took psoriatic arthritis patients longer to receive a formal diagnosis, an average of 112 days versus 89 days for rheumatoid arthritis, the study says.

And people with extensive arthritis affecting five or more joints were less likely to be prescribed antirheumatic drugs if they had psoriatic arthritis compared to rheumatoid arthritis, 54% versus 69%, researchers found.

“With rheumatoid arthritis, symptoms are quickly visible, so the condition is generally diagnosed without too much delay,” Tillett said. “It’s harder to detect inflammation in the joints affected by psoriatic arthritis, as these joints – such as those in the spine – are often not visible to the eye, and it takes an ultrasound to see the damage. Too often, scans don’t happen for some time after the patient starts noticing symptoms.”

Researchers argued that more active screening of people at high risk of psoriatic arthritis needs to take place, using more streamlined diagnostic procedures.

“We need more education around clinicians assessing people with arthritic symptoms and better access to scans,” lead investigator Dr. Rachel Charlton, a life sciences researcher at the University of Bath, said in a news release. “We also need to focus on early intensive treatment before damage sets in – there is a window of opportunity that we may be missing at the moment.”

The scaly, inflamed rashes caused by psoriasis are one potential symptom of psoriatic arthritis, but the rashes don’t need to be present for this type of arthritis to set in, experts point out.

According to the National Institutes of Health, other symptoms can include:

• Joint stiffness, pain and swelling

• Fatigue

• Tenderness where tendons or ligaments attach to bones, such as the back of the heel or the sole of the foot

• Painful, sausage-like swelling of a whole finger or toe

• Nail changes like pitting, crumbling or separation from the nail bed

• Eye inflammation

• Inflammatory bowel disease

More information

The National Institutes of Health has more about psoriatic arthritis.

SOURCE: University of Bath, news release, April 1, 2025