Making a diagnosis of rheumatoid arthritis is often tricky. With no single test that confirms or eliminates the disease, the diagnosis of RA is based on a physical exam, patient history, laboratory tests and often imaging. However, symptoms of RA, such as pain, swelling and fatigue, are not exclusive to the disease. And correct diagnosis is important in choosing an appropriate treatment plan.
A number of diseases, such as lupus, fibromyalgia or Sjögren’s syndrome, may easily be confused with RA or coexist in a patient. Arthritis symptoms might develop following certain infections, such as Lyme disease, tuberculosis, gastrointestinal infection or sexually-transmitted disease. Patients with certain cancers, such as large granular lymphocyte (LGL) leukemia, have an increased incidence of RA and acute leukemia in children may even be misdiagnosed as Idiopathic Juvenile Arthritis.
In addition to the conditions mentioned above, here are seven diseases that could be misdiagnosed as rheumatoid arthritis:
Osteoarthritis is the most common condition misdiagnosed as rheumatoid arthritis according to a recent Colombian study. Of 2478 patients referred by general practitioners to a specialized center with a presumed diagnosis of RA, it was found that 993 patients (40.1%) had been misdiagnosed. The correct diagnosis in 65 percent of the misdiagnosed patients was osteoarthritis (Santos-Moreno 2012).
Potentially confused with seronegative RA, inflammatory osteoarthritis is an aggressive, erosive subtype of primary osteoarthritis that affects 5 to 10 percent of those with OA. The periodic inflammation results in knobby, painful, inflamed knuckles and fingers, while the wrists and metacarpophalangeal joints are not involved. As a form of OA, blood tests show no increases in erythrocyte sedimentation rate (ESR) or C-reactive protein, and antinuclear antibody and rheumatoid factor testing will be negative (Jancin, Internal Medicine News 2013).
Reactive arthritis (ReA)
Reactive arthritis (ReA), formerly called Reiter’s syndrome, is an autoimmune condition that develops in response to an infection. It has been associated with gastrointestinal (GI) infections with Shigella, Salmonella, Campylobacter and other organisms, as well as with genitourinary (GU) infections (especially with Chlamydia trachomatis) spread through sexual contact. Symptoms, which may include arthritis, conjunctivitis, or urethritis, usually occur about one month following infection. ReA affects more men than women.
Psoriatic arthritis (PA)
Symptoms of psoriatic arthritis are similar to those of RA, gout, reactive arthritis and osteoarthritis. Both PA and RA are systemic (body-wide) inflammatory conditions which lead to joint damage. However, RA is a symmetrical disease (affecting the same joints on both sides of the body), whereas PA tends to be asymmetrical and cause skin lesions. RA is associated with rheumatoid nodules and elevated levels of the rheumatoid factor antibody, while PA is not. In RA, joint swelling often occurs over the joints while swelling in PA is more generalized and may produce a sausage-like appearance in fingers or toes. To confirm psoriasis in PA, a skin biopsy may be required and nail symptoms noted. A misdiagnosis of RA may be less critical as many of the treatments for PA and RA overlap.
Palindromic rheumatism (PR)
Palindromic rheumatism, also known as palindromic arthritis, is a syndrome that involves inflammatory attacks on joints, tissue, or muscle that come and go in cycles or episodes. Spontaneous pain can last for a few hours or several days and move from one joint to another. Once the swelling and inflammation disappear, joints go back to normal without damage which helps to distinguish it from RA. Palindromic rheumatism is much less common than RA, with symptoms eventually disappearing in about one in 10 people. PR can be difficult to diagnose and a significant number (1/3 to 1/2) of those with PR may go on to develop RA.
Granulomatosis with polyangiitis (GPA), formerly known as Wegener granulomatosis, is a rare, autoimmune disease that involves inflammation of blood vessels (vasculitis), commonly affecting the eyes and skin. Symptoms may include fatigue, weight loss, fevers, shortness of breath, bloody sputum, joint pains and sinus inflammation. Possible joint pain and episcleritis (inflammation of the eye) caused by Wegener granulomatosis can resemble rheumatoid arthritis and rheumatoid vasculitis, respectively.
Autoimmune hepatitis (AiH)
Autoimmune hepatitis is a chronic disease in which the body’s immune system attacks the liver, causing inflammation and liver damage. It is a serious disease that may worsen over time if not treated and can lead to cirrhosis and liver failure. People who have autoimmune hepatitis often have other autoimmune disorders, such as RA, lupus, Sjögren’s syndrome, Crohn’s disease, ulcerative colitis, celiac disease, type 1 diabetes, Graves’ disease, and Hashimoto’s disease.
Fabry disease, or Anderson-Fabry disease, is a rare, inherited disorder caused by the lack of an enzyme, ceramide trihexosidase, needed to metabolize lipids. Fabry disease may be difficult to recognize as symptoms can be very non-specific, sharing many of the features of rheumatoid arthritis, rheumatic fever, fibromyalgia, dermatomyositis, multiple sclerosis, idiopathic hypertrophic cardiomyopathy, renal failure of unknown cause, Meniere’s disease, and irritable bowel syndrome (Golfomitsos 2012). Typically, males experience severe symptoms, but females may have severe symptoms or be asymptomatic. Fabry disease has been found with higher prevalence in dialysis patients and in cardiac patients with hypertrophic cardiomyopathy (Sunder-Plassmann 2006).
15 Questions: Lupus and Overlap Disease/Syndromes. Lupus Foundation of America (August 2012). Accessed June 13, 2014 at