Psoriatic arthritis is a chronic disease characterized by inflammation of the skin (psoriasis) and the joints (arthritis). The features of this condition include: patchy, raised, red areas of skin inflammation with scaling. Psoriasis often affects the tips of the elbows and knees, the scalp, the navel, and around the genital areas or anus. Approximately 10% of patients who have psoriasis also develop an associated inflammation of their joints. Patients who have inflammatory arthritis and psoriasis are diagnosed as having psoriatic arthritis.
Like Lupus, Psoriatic arthritis is a systemic rheumatic disease that can also cause inflammation in body tissues away from the joints other than the skin, such as in the eyes, heart, lungs, and kidneys. Psoriatic arthritis shares many features with several other arthritic conditions, such as ankylosing spondylitis, reactive arthritis (formerly Reiter's syndrome), and arthritis associated with Crohn's disease and ulcerative colitis. All of these conditions can cause inflammation in the spine and other joints, and the eyes, skin, mouth, and various organs. In view of their similarities and tendency to cause inflammation of the spine, these conditions are collectively referred to as "spondyloarthropathies."
Psoriatic Arthritis does occur as a co-existing disease with Lupus,. The prevalence rate of psoriasis coexisting with SLE is approximately 0.69% of patients with psoriasis and 1.1% of patients with SLE (i.e. rarely). In most reported cases, Psoriatic Arthritis precedes SLE (which may be why your Lupus blood tests are negative right now), but both diseases can occur concurrently.
In studies of patients with both diseases, the most common type of psoriasis that was associated with lupus was plaque-like and the majority of patients developed SLE, while the minority developed discoid lupus erythematosus only. It is not known why the co-existence of Psoriatic Arthritis and Lupus are rare. It is unlikely that the existence of
one (SLE or psoriatic arthritis) protects against the development of the other. It is possible that when a patient with SLE or psoriasis develops arthritis, it is mistakenly related to the underlying disease and an additional diagnosis is not sought.
In summary, the coexistence of SLE and psoriatic arthritis is rare but possible, especially given the fact that both diseases have similar triggering factors (infection, trauma,drugs) that have the potential to precipitate each of these diseases.
With reference to your prescribed medications (Methotrexate, Enbrel, Humira or Remicade). The medications traditionally used to treat PsA have included non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying anti-rheumatic drugs (DMARDs), such as methotrexate, sulphasalazine and leflunomide, sometimes in combination with topical and light therapies for skin manifestations.
1)Methotrexate (MTX) has been used to treat severe and/or disabling psoriasis since the early 1960s. It is also used to treat psoriatic arthritis. MTX was used initially to treat cancer. By chance, it was discovered to be effective in clearing psoriasis.
Generally, MTX is reserved for people with at least 30 percent of their skin covered with psoriasis who are not responsive to, or eligible for, conventional topical or ultraviolet light treatments (UVB and PUVA). The palm of the hand represents about one percent of the skinís surface area.
MTX works best on extensive psoriasis, erythrodermic and acute pustular psoriasis, physically disabling psoriasis of the palms and soles, psoriasis in the elderly, and severe psoriatic arthritis. The majority of patients achieve significant or even complete clearing of their disease with MTX. The clearance or remission can last for a few weeks to a year or more after stopping therapy with Methotrexate.
MTX can be highly effective in reducing symptoms of psoriatic arthritis and arresting joint destruction caused by certain forms of psoriatic arthritis.
2) In 2002, Enbrel (etanercept) was approved by the FDA (the United States Food and Drug Administration) for treatment of people with psoriatic arthritis. Enbrel can be used without methotrexate or can be used in combination with methotrexate in patients who have failed methotrexate alone.
Both Enbrel & Methotrexate ENBREL are medicines that affects your immune system. Both can lower the ability of your immune system to fight infections. However, serious infections have happened in patients taking ENBREL. These infections include tuberculosis (TB) and infections caused by viruses, fungi, or bacteria that have spread throughout the body. Some patients have died from these infections. Your doctor should test you for TB before you take ENBREL and monitor you closely for TB while on ENBREL.
3) Remicade (Infliximab): Treatment with REMICAD has been shown to provide significant and rapid improvements in both the arthritis and psoriasis of patients with active psoriatic arthritis (PsA). REMICADE is a monoclonal antibody that specifically targets and binds to tumor necrosis factor-alpha (TNF-alpha) on the cell membrane and in the blood. Overproduction of TNF-alpha is believed to play a role in RA, Lupus, and a wide range of Immune-Compromised Inflammatory Disorders. Because TNF-α mediates multiple biological processes in the pathogenesis of PsA, a reduction in TNF-α levels was postulated to improve clinical outcomes in patients suffering from PsA. Several anti-TNF-α medications approved for treating and controlling RA were studied in patients with PsA and found to effectively manage both the psoriatic and arthritic manifestations of the disease. This resulted in the clinical development of a variety of TNF-α inhibitors, including infliximab, etanercept, adalimumab, and others, to treat PsA.
Although the factors responsible for development and progression of PsA are still not completely understood, research has provided new insights into the underlying immunological mechanisms of the disease. This research has resulted in the development of new therapies. These include the widely-used anti-TNF-α antagonists and the newer T-cell directed agents prescribed by your doctor. Both drug classes have the potential for better effectiveness than traditional PsA treatments. Unlike older, conventional PsA treatments, these new agents may hinder or inhibit the progression of PsA and thus prevent the erosive joint damage that interferes with the quality of life of many PsA patients. Thus, infliximab, as the first FDA-approved TNF-α monoclonal antibody, may provide a significant advance in treatment for patients with PsA.
I truly hope that providing you information about the drugs prescribed by your doctor gives you a clearer understanding of why they were prescribed and has alleviated some of your fears. Make sure that you discuss their use with your doctor and know that you will be monitored closely while using these treatments!
I wish you the very best
Peace and Blessings
Look For The Good and Praise It!