How Does Psoriatic Arthritis Affect the Spine?
Psoriatic arthritis (PsA), the chronic inflammatory arthritis associated with psoriasis, can affect any joint in the body. The disease varies widely among patients. When it affects the spine, it is often referred to as one of the following:
PsA in the spine may also be called axial arthritis. PsA in the spine may present as inflammatory low back pain and show evidence of inflammation on x-rays, although MRI is generally the gold standard for imaging axial disease.1,2
Psoriatic spondylitis shares similarities with ankylosing spondylitis. Both are inflammatory diseases that may have a link to the HLA-B27 gene, which is a gene that is known to predispose people to several rheumatic diseases. While there are several genes linked to PsA, the highest predictive value is found with HLA-B27.3
How often does PsA affect the spine?
Up to 40% of patients with PsA have spine involvement, or axial disease.2
What symptoms occur when the spine is involved in psoriatic arthritis?
When PsA affects the spine, patients often experience back pain and stiffness, which may be worse in the morning, or after periods of rest. Pain may be throbbing at the affected joints. Sacroilitis causes low back pain, while spondylitis can involve the lower or upper back, or neck. Patients may also experience reduced range of motion.1,3
Ways to alleviate pain or disability
For moderate to severe disease, treatments that target joint disease in PsA can reduce symptoms and prevent disease progression. Recommended treatments include disease-modifying anti-rheumatic drugs (known as DMARDs). Non-biologic DMARDs, such as methotrexate, leflunomide, or sulfasalazine, have demonstrated efficacy for peripheral arthritis but not for axial disease. Biologic DMARDs that have proven effective in clinical trials include ustekinumab (Stelara), brodalumab (which is awaiting FDA approval), and secukinumab (Cosentyx). Other DMARDs 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). 4 The FDA has also recently approved Inflectra (infliximab-dyyb), a biosimilar to infliximab, for the treatment of PsA.5
Physical and occupational therapy can also be critical treatment approaches to both protect the involved joints and maintain function.1