Joint Pain, Stiffness, and Swelling With Psoriatic Arthritis
One of the classic features of psoriatic arthritis (PsA) is joint pain, swelling and stiffness. However, PsA is known for its diversity in presentation and in its response to treatment. Different patients can have very different symptoms, with varied progression of the disease. In addition to joint pain, patients with PsA may experience inflammation at the tendon and ligament attachment points, fatigue, and changes to their nails.1
Characteristics of joint involvement in PsA
PsA causes inflammation in the joints, which can create swelling, pain, and stiffness. People with PsA may experience a loss of normal function in the affected joints, which can make it difficult to perform even normal tasks of daily living, such as grooming, dressing, or shopping.2
PsA can affect the joints asymmetrically, occurring on one side of the body and not the other. For example, one knee might be inflamed while the other knee is unaffected. However, people with PsA can also experience symmetrical joint involvement, occurring on both sides of the body.3
PsA often begins in the distal joints, those farthest away from the core of the body, such as the interphalangeal joints in the fingers and toes. The disease can cause significant swelling in the fingers and toes, creating a sausage-like appearance, called dactylitis.1,3
Joint swelling – PsA causes inflammation at the joints. In some cases, patients develop dactylitis, a swelling of the fingers or toes in a sausage-like formation.1 Another common feature of PsA is dactylitis (seen in about 35% of people with PsA), often called “sausage digit.” This is a very painful and sometimes disabling problem which involves swelling of an entire finger or toe. We now know that dactylitis is due to swelling and inflammation of all the tissues within a digit including the joints, tendons, entheses and bone.
- Joint stiffness – With the inflammation of PsA, joints become stiff, especially first thing in the morning or after a period of rest.2
- Redness of joint – Many people with PsA experience redness of the affected joints.2
- Heat at joint – The inflammation of PsA can also create a feeling of heat at the joint.2
- Loss of normal function – PsA can cause a noticeable loss of normal functions, including daily tasks of grooming, shopping, and other activity.3
Inflammation in the joints leads to pain
Immune responses – both normal and abnormal as seen in PsA – that cause inflammation are painful because the excess blood flow and the substances secreted by the white blood cells and excess fluid irritate the nerves in the area, sending pain signals to the brain.
Progression of the disease
The pattern of joint involvement in PsA can change and evolve over time. Some patients go from asymmetrical oligoarthritis to symmetrical polyarthritis. With effective treatment, some patients with polyarticular disease may become oligoarticular.3
Approximately 5% of people with PsA will progress to arthritis mutilans, the most severe, destructive form of PsA. Arthritis mutilans is characterized by digital shortening, leading to deformity and loss of function of the digits.3
Joint fluids (synovial pathology)
Synovial tissue is found between joints bound by a fibrous capsule whose inner membrane secretes a lubricating fluid, known as synovial fluid. These types of joints allow for a wide range of movement and are found in the wrist, elbow, shoulder, knee, and hip.4
When PsA affects the synovial tissue, inflammation occurs due to an increase in immune system cells, particularly white blood cells (T-cells, B-cells, and some macrophages).1 While there are no specific diagnostic tests for PsA, one abnormality that can be definitively tested for is found in the synovial fluid.5
How is PsA in the joints diagnosed?
PsA is often diagnosed with the use of imaging techniques, including x-ray, MRI (magnetic resonance imaging), and ultrasound. Ultrasound and MRI have been shown to be more sensitive than x-ray to detect inflammatory changes in patients with PsA. Ultrasound is useful for assessing structural changes and detecting abnormal blood flow. MRI allows visualization of soft tissue as well as bony changes.1,3
How is PsA in the joints treated?
Minor pain and stiffness of mild PsA can be alleviated with non-steroidal anti-inflammatory drugs (NSAIDs). In addition, injections of corticosteroids may be used.6
For moderate to severe disease, treatments that target joint disease in PsA can reduce symptoms and prevent disease progression, including deformity and loss of function. Recommended treatments include disease-modifying anti-rheumatic drugs (known as DMARDs). The first step for treatments is usually DMARDs such as methotrexate, leflunomide, or sulfasalazine. Other treatments include medicines that target tumor necrosis factor (TNF), a chemical that produces a wide range of inflammation in PsA. Examples of TNF blockers include etanercept (Enbrel), adalimumab (Humira), infliximab (Remicade), golimumab (Simponi), and certolizumab pegol (Cimzia). Other DMARDs that have proven effective in clinical trials include ustekinumab (Stelara), brodalumab (which is awaiting FDA approval), and secukinumab (Cosentyx).3 The FDA also approved Inflectra (infliximab-dyyb), a biosimilar to infliximab, for the treatment of PsA.7
Physical and occupational therapy can be critical treatment approaches to both protect the involved joints and maintain function.6 A physical therapy program generally includes various exercises and stretches, applied heat and/or cold, orthotics, assistive devices for gait, and possible vocational readjustments.5
Surgical care may be indicated for severe disease. Arthroscopic surgery to the synovial capsule has been shown to be effective, and joint replacement or reconstructive surgery may be necessary.5