One patient described the pain as like walking across jagged, scorching rocks. Another said she was in so much pain she had to take time off of work. British writer Dennis Potter suffered from his psoriasis causing his skin to flake off his body like snow, while enduring the arthritic pain of having his jaw muscles and fingers clench from arthritis. Potter’s hands were so badly damaged that he could only write if someone taped a pen to his fist.
These dramatic descriptions indicate what it can be like to suffer from psoriatic arthritis, a distinct, complex, sometimes crippling, systemic disease associated with the skin condition psoriasis. While many are familiar with osteoarthritis or rheumatoid arthritis, psoriatic arthritis garners far less attention. But not only is this illness often disabling, it’s also tricky to diagnose, and its treatment can be hard on patients.
Psoriatic arthritis is related to psoriasis, a chronic inflammatory disease—in which the immune system attacks the body’s own tissues. For most psoriasis patients, the skin is targeted, resulting in red, scaly patches. For unknown reasons, in up to 30 percent of patients with psoriasis, the immune system also turns against the joints. The joint disease may show itself as swollen and painful fingers or toes, but it can also harm other joints throughout the body. Like other types of arthritis, psoriatic arthritis can destroy the joints.
With no conclusive test for psoriatic arthritis, patients may have to endure joint pain and swelling for years before they receive a diagnosis.
With no conclusive test for psoriatic arthritis, patients may have to endure joint pain and swelling for years before they receive a diagnosis. Once a diagnosis is established, doctors do have some therapies to deploy. One family of treatments, oral disease-modifying antirheumatic drugs (DMARDs), may help treat the joint swelling and tenderness by suppressing the immune system. Traditional DMARDs are systemic medicines (working throughout the body) that for the most part were originally developed to treat other diseases and then repurposed. None are approved by the U.S. Food and Drug Administration for the treatment of patients with psoriatic arthritis. A newer class of DMARDs is biologics, which can block proteins that play a role in inflammation.
Both kinds of DMARDs have drawbacks. Traditional DMARDs have not been proven to alleviate pain and stiffness in the neck, spine and pelvis. Nor have they been shown to be fully effective in treating enthesitis, a type of inflammation that is unique to psoriatic arthritis, and affects the area where tendon and ligaments attach to the bone. Some have been associated with serious organ toxicity, which requires laboratory monitoring and may limit the length of time that the treatment may be used. Meanwhile, biologics are burdensome for patients because they have to be injected or given intravenously and may increase the likelihood of serious infections or malignancies.
What physicians and patients need right now are more choices to treat this disease. To this end, research into the specific molecules that lead to psoriatic arthritis is offering hope to patients who have limited treatment options for their debilitating disease.