Detailed write-ups on Psoriatic arithritis

What Is Psoriatic Arthritis?

Psoriatic arthritis, a chronic disease, is a form of inflammatory arthritis that affects between 10% and 30% of patients who have psoriasis (National Psoriasis Foundation, USA). The majority of patients with psoriatic arthritis developed the skin conditions - psoriasis - first, and were later diagnosed with psoriatic arthritis. However, in about 20% of cases arthritis symptoms may emerge beforehand. If the arthritis symptoms emerge many years before the skin symptoms an accurate diagnosis may be difficult.

Some patients may just have psoriasis symptoms for a couple of decades before the development of arthritis.

People with psoriatic arthritis have inflammation of the skin (psoriasis) and joints (arthritis).

Psoriatic arthritis may emerge at any time, but it most commonly appears between the ages of 30 and 50 years. The risk of developing the condition is slightly higher for males than females.

Psoriatic arthritis is a systemic disease - it can affect any part of the body. Inflammation of body tissues, apart from the joints or skin are possible, including the eyes, heart, kidneys and lungs.

There is no current cure for psoriatic arthritis. Treatment is aimed at controlling symptoms and preventing damage to the joints.

According to Medilexicon's medical dictionary:

Psoriatic arthritis is “the concurrence of psoriasis and polyarthritis, resembling rheumatoid arthritis but thought to be a specific disease entity, seronegative for rheumatoid factor and often involving the digits”

What are the signs and symptoms of psoriatic arthritis?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor detect. For example, pain may be a symptom while a rash may be a sign.

Psoriatic arthritis, like psoriasis, is a progressive, chronic condition, in other words, it is long-term and gradually gets worse. Patients may have periods when symptoms get better or go away altogether (remission), while on other occasions symptoms worsen. Typically, both joint and skin symptoms come and go at the same time.

The most common signs and symptoms of psoriatic arthritis include:

• The affected joints are painful
• The affected joints are swollen (inflamed)
• When touched, the affected joints feel warm
• Psoriasis symptoms (click here to see Psoriasis Symptoms section)

According to The Mayo Clinic, USA, there are five types of psoriatic arthritis. Over time, patients may experience many of them.

• Asymmetric psoriatic arthritis - it is the mildest form of the disease. The patient has either:
• affected joints on only one side of the body
• affected joints on each side, but they are different joints
The joints most commonly affected are those in the hip, ankle, wrist or knee. Joints are typically tender and red. In most cases, fewer than five joints are affected.

Sometimes arthritis may develop in the hands and feet. If the tendons become inflamed the fingers and toes may look like small sausages (dactylitis).

Patients may experience intermittent joint pain which usually responds to medical treatment. Although this type of psoriatic arthritis is mild, some patients may develop disabling disease.


• Symmetric psoriatic arthritis - in most cases at least five joints are affected, the same joints on each side of the body. Symmetric psoriatic arthritis is more common among females than males. Generally, the symptoms are severe.
  Symmetric psoriatic arthritis is much like rheumatoid arthritis, but usually milder and with less deformity. It can be disabling.
• Distal interphalangeal (DIP) joint predominant psoriatic arthritis - also known as DIP psoriatic arthritis. This is a rare type of psoriatic arthritis. The majority of patients are male. The toe or finger distal joints are affected (the top joint of the finger, closest to the nails). It may sometimes be confused with osteoarthritis.
  Nails will typically thicken; there will also be pitting and discoloration.
• Spondylitis - there is pain in the spine. The patient’s neck, lower back, sacroiliac joints (in the pelvis) or spinal vertebrae are stiff and inflamed. Ligaments and tendons which attach to the spine may also become inflamed. Over time the patient may find it harder to move about.
• Arthritis mutilans - a severe, deforming, destructive and disabling type of arthritis which affects less than 5% of psoriatic arthritis patients. Arthritis mutilans mainly affects the small joints of the hands and feet. It is often linked to neck or lower back pain. Over time, the small bones in the hands, especially the fingers are destroyed.

What are the risk factors for psoriatic arthritis?

A risk factor is something which increases the likelihood of developing a condition or disease. For example, obesity significantly raises the risk of developing diabetes type 2. Therefore, obesity is a risk factor for diabetes type 2. Risk factors for psoriatic arthritis include:

• Psoriasis - people with psoriasis have a significantly higher risk of developing psoriatic arthritis, compared to other individuals. Especially patients with psoriasis lesions in their nails.
• Genetics - a significant number of patients with psoriasis have a close relative with the same condition.
• Age - people aged between 30 and 50 years have a higher risk of developing the condition. However, psoriatic arthritis may emerge at any age.
• Gender
• DIP arthritis and spondylitis occurs more frequently in males than in females.
• Symmetric arthritis occurs more frequently in females than in males.

What are the causes of psoriatic arthritis?

Although experts are not sure what the exact cause of psoriatic arthritis is, most believe a combination of genetic, immune system and environmental factors are involved.

• A specific gene marker - a gene marker named HLA-B27 is found in a significant number of patients with psoriatic arthritis who have arthritis of the spine (spondylitis).
• There are blood tests which can determine whether the patient carries the HLA0B27 gene.
• Other genes - scientists have identified other genes which are more commonly found in patients with psoriatic arthritis.
• Immune system changes - experts believe changes in the immune system play an important part in the development of psoriatic arthritis. Patients with AIDS typically have a low number of T cells (a type of immune cell). A decline in the number of T cells is linked to a significantly higher risk of eventually developing psoriatic arthritis if you already have psoriasis.
• Environmental factors - experts believe certain environmental factors, as well as infectious agents may be involved in the development of psoriatic arthritis. Current research may eventually provide more information on this.
  
  Physical trauma, a viral or bacterial infection may trigger psoriatic arthritis in individuals with an inherited tendency.
• TNF (tumor necrosis factor) - this substance causes inflammation in rheumatoid arthritis. Patients with psoriatic arthritis have high blood levels of TNF in their joints and skin. It is believed that TNF plays a role in psoriatic arthritis.

Diagnosing psoriatic arthritis

There is not specific test that can diagnose psoriatic arthritis. A diagnosis will be considered if a patient with psoriasis has inflammatory arthritis signs and symptoms (typical inflammatory arthritis of the spine and/or other joint). Some other conditions will need to be ruled out, such as osteoarthritis or rheumatoid arthritis.

• X-rays - an X-ray can help identify changes that take place in psoriatic arthritis, but not in most other arthritic conditions.
• Joint fluid test (arthrocentesis) - a sterile needle is used to withdraw (aspirate) fluid from an inflamed joint, usually the knee, and then sent to the lab. If uric acid crystals are present it is more likely the patient has gout.
• Erythrocyte sedimentation rate (ESR or sed rate) - this blood test detects and monitors inflammation in the body by measuring the rate at which red blood cells in a test tube separate from blood serum over a set period, becoming sediment in the bottom of the test tube. A high sedimentation rate is linked to more inflammation. In other words, if the red blood cells sink faster to the bottom of the test tube, it could mean that the patient has an inflammatory condition. As many forms of arthritis and rheumatic diseases cause inflammation in the body, this test can only confirm the presence of inflammation (not necessarily psoriatic arthritis).
• RF (rheumatoid factor) - this is a protein made by the immune system; an antibody. It is commonly present in the bloodstream of patients with rheumatoid arthritis. Patients with psoriatic arthritis do not have RF in their blood. This test helps the doctor determine whether the patient has rheumatoid arthritis or psoriatic arthritis.

What are the treatment options for psoriatic arthritis?

Treatment is aimed at controlling swelling (inflammation) in the affected joints, as well as alleviating pain and helping with disability. Usually, a multidisciplinary approach is needed to treat both joint and skin symptoms.

Medications

• NSAIDs (non-steroidal anti-inflammatory drugs) - generally, the first medications prescribed for psoriatic arthritis. Examples include aspirin and ibuprofen. They help reduce pain, inflammation as well as the early morning symptoms of stiffness. Higher dose NSAIDs require a prescription. When taken in high doses or over a long period they may cause complications. Side effects may include:
• A higher risk of bruising
• Gastric ulcers
• Hypertension - high blood pressure
• Kidney damage
• Liver damage
• Some heart problems
• Stomach bleeding
• Tinnitus - ringing in the ears
• Corticosteroids - these are effective at reducing inflammation, pain, as well as slowing down joint damage. They are usually recommended when NSAIDs have not helped. If the patient has a single inflamed joint the doctor may inject the steroid into the joint. Effective relief is usually felt rapidly and the effect can last from weeks to months, depending on the severity of symptoms.
  
  Examples include prednisone and methylprednisolone (Medrol). Corticosteroids are generally used for acute symptoms (short term flare ups) - the dosage is then gradually reduced (tapered off). Long term use can have serious side effects, including:
• A higher risk of bruising
• Cataracts
• Diabetes
• Round face
• Weight gain
• Osteoporosis
• Glaucoma
• Muscle weakness
• Thinning of the skin
• DMARDs (disease-modifying antirheumatic drugs) - this medication may slow down the progression of the arthritis, as well as preventing permanent damage to the joints and other tissues. The earlier the patient starts taking a DMARD the more effective it will be.
  
  It may take from four to six months before the patient starts noticing any beneficial effects. It is important to keep taking the medication even if initially it does not appear to be working. Some patients may have to try different types of DMARD before hitting on the most suitable one. This medication is usually taken indefinitely.
  
  Examples include leflunomide (Arava), methotrexate (Rheumatrex, Trexall), sulfasalazine (Azulfidine), minocycline (Dynacin, Minocin), and hydroxychloroquine (Plaquenil). Side effects may include:
• Liver damage
• Bone marrow suppression
• Lung infections (severe)
• Immunosuppressants - suppressing the immune system helps reduce the damage to good tissue. Examples include cyclosporine (Neoral, Sandimmune, Gengraf), azathioprine (Imuran, Azasan), and cyclophosphamide (Cytoxan).
• Tumor necrosis factor-alpha inhibitors (TNF-alpha inhibitors) - the human body produces tumor necrosis factor-alpha (TNF-alpha). TNF-alpha is an inflammatory substance. TNF-alpha inhibitors are used for the reduction of pain, morning stiffness and swollen or tender joints. Results are usually noticed within two weeks of starting treatment. Examples include Etanercept (Enbrel), infliximab (Remicade) and adalimumab (Humira). Possible side effects include:
• A higher risk of infection
• Blood disorders
• Congestive heart failure
• Demyelinating diseases - erosion of the myelin sheath that normally protects nerve fibers, exposing the fibers, resulting in problems in nerve impulse conduction. This may affect several physical systems.
• Irritation at the injection site
• Lymphoma

Surgery - if other treatments have not worked, the doctor may recommend surgery on a joint - however, this is rare.

What are the possible complications for psoriatic arthritis?

• Arthritis mutlians - an extremely severe form of chronic rheumatoid arthritis, in which the bones are reabsorbed, resulting in the collapse of soft tissue. When the hands are affected it can cause a phenomenon called telescoping fingers; the feet may also be affected. Patients with other arthritic conditions, such as osteoarthritis or rheumatoid arthritis in the joints of the fingers have a higher risk.
• Dactylitis - sausage-like swelling of the fingers and/or toes. Some patients may find it very hard to find shoes that fit.
• Enthesopathy - there is pain at the point where tendons and ligaments attach to bone. In patients with psoriatic arthritis, symptoms may be felt at the back of the heel or in the sole of the foot.
• Spondylitis - inflammation of the joints between the vertebrae and the spine, and the joints between the spine and the pelvis. This causes neck and back pain.