How Are Tendons & Ligaments Affected?
One of the differentiating characteristics of psoriatic arthritis (PsA) is that it can cause inflammation of both joints and the attachment points of tendons and ligaments. These attachment points are known as entheses, and the inflammation of these points is called enthesitis.1,2
A genetic component associated with both enthesitis and symmetrical sacroiliitis (PsA at the joint between the spine and the pelvis) is the HLA-B27 gene. This gene is not a cause of psoriatic arthritis but is highly correlated with several inflammatory diseases. In PsA, the HLA-B27 gene is associated with an early development of the condition.1
Enthesitis is often diagnosed using ultrasound or MRI (magnetic resonance imaging), which are more sensitive than x-ray to detect inflammatory changes in people with PsA. Ultrasound is useful for detecting structural changes and abnormal blood flow. MRI allows visualization of soft tissue as well as bony changes.1,3
How does this condition affect the tendons & ligaments?
Enthesitis occurs in up to 50% of people with PsA.4 Symptoms of PsA in the tendons and ligaments (enthesitis) include pain and inflammation. When enthesitis affects the heel of the foot, it is known as Achilles tendonitis.
At the bottom of the foot, enthesitis can cause plantar fasciitis. Enthesitis can also occur in the fingers, toes, pelvis, knees or upper body.5,6
PsA can be asymmetrical, occurring on only one side of the body. For example, all the joints in one finger on the left hand may be affected while the same finger on the right hand is unaffected. PsA can also be symmetrical, with the same joints affected on both sides of the body.2
PsA and enthesitis are chronic and can have periods of remission and flares.6
What are options for pain management?
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.5
For moderate to severe disease, treatments that target joint disease in PsA frequently can reduce symptoms and prevent disease progression. 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), and secukinumab (Cosentyx).1
The FDA has also recently approved Inflectra (infliximab-dyyb), a biosimilar to infliximab, for the treatment of psoriatic arthritis.7Physical and occupational therapy can be critical treatment approaches to both protect the involved joints and maintain function.5