Psoriatic Arthritis: Everything You Need to Know

Psoriatic arthritis is a rare disease that quickly worsens when left untreated. Let's see what the specialists say about it.
Psoriatic Arthritis: Everything You Need to Know

Last update: 09 August, 2021

Psoriatic arthritis is a chronic disease that affects the body’s joints. According to the National Psoriasis Foundation, it’s estimated to affect up to 30% of patients diagnosed with psoriasis. Although it can start at any age, it most often develops in adults between the ages of 30 and 50.

At first, the researchers thought that it was the coexistence of two different diseases (arthritis and psoriasis), but today it’s widely accepted that it’s a condition with its own characteristics. Today, we’ll show you everything that we know about it.

Causes of psoriatic arthritis

As Johns Hopkins Medicine points out, doctors haven’t found the exact causes of psoriatic arthritis. It’s believed that the disease can occur due to multiple factors, among which genes, environmental factors, and immune disorders play a leading role.

Most patients who develop this type of arthritis have a first-degree relative who suffers from it. Studies in this regard indicate that this pattern is repeated in up to 95% of cases, with evidence that transmission maintains a non-Mendelian line (as in psoriasis). However, this predisposition alone isn’t enough to activate the disease.

An external catalyst is needed for the final manifestation. An infection, the intake of some drugs, or a virus, according to some hypotheses, can trigger the inflammatory process.

Alcohol, smoking, endocrine disorders, stress, and other factors have also been singled out by researchers as possible culprits. It isn’t uncommon to find that, in some cases, it’s impossible to find a cause.

Virus that triggers psoriatic arthritis.
Viral infections could be triggers for patients predisposed to psoriatic arthritis.

Types of psoriatic arthritis

The disease doesn’t have one single manifestation. Specialists have identified several types with different characteristics, evolutions, and prognoses.

1. Predominant distal interphalangeal

On average, 5% of psoriatic arthritis cases correspond to this variety. It affects the joints of the hands and feet, especially those close to the nails. Its presentation is usually asymmetrical and its evolution progressive.

2. Asymmetric oligoarticular

The asymmetric form is the most common manifestation of the disorder. 70% of diagnosed patients have this variety.

Studies in this regard indicate that it affects up to 5 joints at the same time. These can be interphalangeal or metacarpophalangeal.

3. Symmetric polyarthritis

The symptoms, in this case, are identical to those of rheumatoid arthritis, so that the two are often confused. It’s characterized by developing symmetrical manifestations in 5 or more joints. On average, 15% of cases correspond to this type.

4. Ankylosing spondylitis

Ankylosing spondylitis is one of the most problematic divisions, as the line that divides it from classic spondylitis is a very fine one. This has caused researchers to spend much time investigating it, and many articles have been published. Much of the course of its evolution is unknown.

5. Mutilating arthritis

The most serious presentation of the disease is the mutilating one. It causes deformities in the hands and feet and destruction of the distal parts of the bone. Its incidence is around 5% of patients and some studies suggest that it’s more frequent at an early age.

Symptoms of psoriatic arthritis

Each type of psoriatic arthritis has different symptoms. Even among patients diagnosed with the same variant, the clinical manifestations differ.

This represents an obstacle for the diagnostic process, as there are no well-defined signals between them. In general, and following an article in Arthritis Australia, the symptoms shared in any of the forms of the disease are the following:

  • Pain, stiffness, and swelling in one or more joints of the body
  • Changes in the appearance of the nails (color, texture, and thickness)
  • Pain in the eyes (sometimes accompanied by redness)
  • A sensation of inflammation in the tendons (often accompanied by pain)
  • Stiffness in the buttocks, lower back, or neck

If the disease is at an advanced stage, you may experience limb atrophy. This limits a person’s movements and compromises quality of life.

Diagnosis of psoriatic arthritis

There’s no test to diagnose psoriatic arthritis. The method used is to rule out other explanations for the symptoms.

The process can be extended if the doctor doesn’t find clear patterns that allow them to differentiate this type from other rheumatic manifestations. According to the American College of Rheumatology, some of the tests that can be carried out are the following:

  • Magnetic resonances
  • X-rays
  • Ultrasounds
  • Computed tomography
  • Urine and blood tests
  • Skin biopsy

All this will allow the doctor to distinguish if the inflammatory process is caused by other conditions (such as lupus, osteoarthritis, rheumatoid arthritis). Reviewing the person’s medical history is very important. If there’s a prevalence of psoriasis in the family, the signs are stronger for confirmation.

Treatment of psoriatic arthritis

There’s no cure for psoriatic arthritis, but it’s a disease that can be treated. Therapies should begin as soon as possible, since the condition usually has an accelerated rate of progression. Arthritis Ireland lists the following options among the most used.

Disease-modifying antirheumatic drugs (DMARDs)

DMARDs are the main therapy to stop the inflammatory process and prevent joint degeneration. Most are slow-acting, so it may take several weeks or months for improvement to show. The most used are methotrexate and leflunomide.

Phosphodiesterase 4 inhibitors

In general, they’re used as alternatives to the previous ones, especially in patients who don’t report improvements after a couple of months. Although it’s a relatively new group of drugs, studies support its use in the treatment of inflammatory diseases. One of the most used is apremilast.

Biological therapies

These are part of the FAME, but, in practice, many researchers classify them separately, due to their actions. Their incorporation is recent and they’re used when no progress has been made with the previous options. Most are given by injection or drip.

Intravenous medication for psoriatic arthritis.
Most biological drugs are administered intravenously in medical and hospital settings.

Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs are used to treat pain and inflammation. They’re part of the main therapy, especially in patients who develop chronic manifestations.

Ibuprofen, aspirin and paracetamol are the most used. Although there are dozens of options.

Steroid injections

In some cases, the doctor may approve steroid injections. They’re used only in seriously ill patients or when there’s no relief of pain or inflammation through the drugs already described. They’re applied in a focused way in the area where the disease is concentrated.

Psoriatic arthritis is a complex disease

The lack of a specific definition on the position that psoriatic arthritis should have in the classification of diseases shows that it’s a complex condition. At the onset of symptoms, it’s common for professionals to fail to consider it.

Joint pain needs to be studied carefully. The sooner confirmation is reached, the easier it will be to establish an approach that improves quality of life.

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