Psoriatic arthritis is a type of psoriatic disease. It is an inflammatory condition that involves pain and swelling in joints on one or both sides of the body. Psoriatic arthritis stems from a problem in the immune system.

People with severe symptoms of psoriatic arthritis (PsA) often find that they worsen over time, especially without treatment.

There is a risk of permanent joint damage. However, early treatment can prevent or slow the progression of PsA.

People with mild symptoms may continue to experience them without these symptoms significantly worsening.

This article looks at how the symptoms of PsA may appear.

PsA causes pain, swelling, and a feeling of warmth in the joints and other symptoms throughout the body. It can affect a person’s mobility, quality of life, and overall health.

Here are some symptoms a person may notice.

Swollen fingers and toes

PsA can cause dactylitis.

This involves painful swelling in the fingers and toes that can make them resemble sausages. Swelling and deformities can appear in the hands and feet before significant joint symptoms appear.

Dactylitis affects around 1 in 3 people with PsA. It can be a sign of how severely PsA affects the individual.

However, it can also occur with other conditions, including infections such as tuberculosis (TB), sarcoidosis, and sickle cell disease.

Eye problems

Inflammation can cause redness and irritation in the eyes due to uveitis. Uveitis causes inflammation in the eye. It affects around 7–20% of people with psoriasis and is more common in those with PsA.

Symptoms of uveitis include:

It can lead to vision loss in time, but treatment can help prevent this.

Joint pain and swelling

Joint pain, inflammation, and swelling are key signs of PsA, although a person may notice other symptoms first.

There are different types of PsA, and the features of joint swelling can vary. However, 60% of people with PsA have asymmetrical joint involvement initially. In other words, it does not usually affect the same joints on both sides of the body. In addition, symptoms usually start by affecting five or fewer small or large joints.

However, polyarticular arthritis can develop over time when symptoms affect many joints, usually symmetrically.

Lower back pain

Inflammation can develop in the joints between the bones of the spine and in the pelvis, including the sacroiliac joint. This is known as inflammatory axial disease or axial spondyloarthritis.

Lower back pain due to inflammatory axial disease affects up to 78% of people with PsA.

Symptoms include pain and swelling in the joints in the lower back that connect the spine to the pelvis.

Foot pain and swelling

Enthesitis involves inflammation where the ligaments, tendons, and joint capsules attach to the bone. It is an early sign of PsA. Symptoms include pain and swelling.

In the foot, people may notice these symptoms toward the back of the heel and in the sole.

An MRI or ultrasound may show thickening of tendons, calcification, erosion of tissue, and bony spurs in places where tendons and ligaments meet a joint.

Skin changes

Between 6% and 41% of people with psoriasis develop PsA. For around 68% of people with PsA, psoriasis skin symptoms occur first. In 15%, they appear around the same time, and in 17%, skin changes develop after PsA appears.

Symptoms of skin psoriasis include plaques or lesions on the skin.

Features depend on the type of psoriasis but most commonly:

  • are raised
  • are covered with flaky, silvery scales
  • may be itchy and inflamed
  • occur on the trunk, arms, legs, and scalp
  • tend to come and go, alternating between periods of flare and remission

Uveitis, a type of eye inflammation, may also occur.

People with a history of skin psoriasis have a higher risk of developing PsA than those without.

Nail changes

Around 80–90% of people with PsA also have nail psoriasis. Nail symptoms also affect 10–55% of those with skin symptoms.

Nail psoriasis can look like a fungal infection but does not involve a fungus or other pathogen, and it is not contagious. It results from an overproduction of skin cells due to a faulty immune reaction.

Symptoms can range in severity.

They may appear on one or several nails and include:

  • nail pitting and crumbling
  • ridging and splitting of nails
  • thickening or lumpiness due to the overgrowth of skin cells below the nail
  • the separation of the nail from the nail bed, known as onycholysis
  • discoloration
  • red spots in the “half moon” or lunula at the base of the nail

Nail changes can be a sign of underlying psoriatic disease and possibly PsA.

Experts do not know what causes PsA, but it likely results from a combination of genetic and environmental factors.

A person with a genetic predisposition may develop PsA if they have a risk factor, such as:

  • a history of psoriasis
  • a family history of psoriatic disease
  • being aged between 30–50, the most common age for PsA to appear
  • exposure to an infection, such as strep throat, which can trigger the first symptoms
  • obesity, which like PsA, involves inflammation
  • a history of smoking
  • alcohol consumption
  • stress
  • trauma, such as a blow to a joint

Anyone with psoriasis could consider talking with a doctor about the possibility of developing PsA, especially if they have a family history of psoriasis or PsA, symptoms affecting the nails, or a combination.

A doctor will look for the following:

  • swollen and painful joints
  • skin and nail changes typical of psoriasis
  • patterns of arthritis that characterize PsA

They may also recommend:

  • an X-ray to assess damage to the joints and bones
  • an MRI or ultrasound, as these can detect tissue damage that appears before bone changes occur
  • blood tests for markers of inflammation to help rule out other conditions
  • a skin biopsy to check for skin psoriasis, a strong risk factor for PsA

Treatment will depend on the severity of symptoms, among other factors.

Treatment aims to:

  • manage symptoms
  • slow the progression of the disease
  • lower the risk of flares
  • reduce the severity of symptoms

Current guidelines recommend:

Drugs for PsA can have adverse effects, and a doctor will work with the individual to identify the best option or combination of approaches.

PsA can be mild or severe. Severe cases can worsen over time and lead to permanent joint damage. They can also affect a person’s mobility, quality of life, and overall health.

In addition, people with PsA seem to have a higher risk of various conditions related to metabolic syndrome, including obesity, type 2 diabetes, and cardiovascular disease.

New treatments can effectively manage symptoms in many cases. For this reason, it is essential to seek an early diagnosis and treatment if possible.

Here are some questions people often ask about PsA symptoms.

What do the early signs of psoriatic arthritis look like?

People who develop PsA often have skin or nail symptoms of psoriasis before arthritis appears. Other signs of PsA include:

  • pain and swelling in the fingers or toes
  • pain and stiffness in the joints
  • pain where the tendons and ligaments meet the joints
  • pain and redness in the eyes.

What has similar symptoms to psoriatic arthritis?

Many types of arthritis have similar symptoms to PsA, including osteoarthritis and rheumatoid arthritis (RA). However, PsA has some specific features, such as dactylitis, which does not tend to occur with RA. It often happens with skin, nail, or eye symptoms, it is usually asymmetrical to start with, and it involves inflammation where the tendons and ligaments meet the joints.

Psoriatic arthritis (PsA) is a psoriatic disease. It has links with skin psoriasis, nail psoriasis, and uveitis, a type of eye inflammation. Noticeable signs include pain and swelling in the fingers, toes, and joints.

Anyone with a family or personal history of psoriatic disease should ask their doctor about the possibility of developing PsA, especially if they also have nail changes and experience joint pain.