A Fine Distinction: RA vs. Lupus

A friend of mine was struggling to determine, based upon her symptoms, whether she had Rheumatoid Arthritis or Lupus. I never thought they were that similar - but upon further research, it looks like there are alot of cross-over symptoms. Come to think of it, for a short period, it was thought that perhaps I had RA rather than Lupus. Take this quick quiz and see if you know the differences between the two:

http://arthritis.about.com/library/quiz/blquizralupus.htm

Also - check out this story, courtesey of Medscape: Today, regarding the subject:

A 52-year-old woman sees her primary care clinician reporting pain and swelling of the metacarpophalangeal (MCP) joints and proximal interphalangeal (PIP) joints for the past 2 months. The pain primarily involves the second and third MCP joints bilaterally, PIPs number 2 though 5, and both wrists, and is symmetrical. She reports morning stiffness that lasts about 45 minutes and experiences afternoon fatigue.

Physical examination is normal including skin, abdomen, and joints other than the MCP joints and PIP joints and confirms swelling and pain there. [1]Examination of the patient's feet is normal. All of the patient's vital signs are within the normal ranges.

Rheumatoid arthritis (RA) must be differentiated from musculoskeletal and other complaints that may be caused by mechanical disease (tendonitis) or osteoarthritis, psoriatic arthritis, or lupus, during the first presentation to the healthcare professional. It is likely that the first encounter during which the patient presents RA symptoms will be at the PCP office, hence recognition of signs of RA in primary care are critical to early detection, treatment initiation, and referral. Symptoms of RA occur symmetrically, as an additive polyarthritis, with sequential addition of involved joints. This is in contrast to the migratory arthritis typical of systemic lupus erythematosus, or episodic arthritis typical of gout. RA must be distinguished from lupus and psoriatic arthritis and from other disorders.

To establish a diagnosis of RA, the patient history, physical examination, and key laboratory and radiographic findings are used. Table 1 shows the clinical criterion for a diagnosis of RA. Four of these criteria must be present for a duration of at least 6 weeks.[2] It is important to also include an appropriate review of systems to diagnose RA.

Table 1. Clinical Criteria for Rheumatoid Arthritis: Four for a Minimum of 6 Weeks
1. Morning stiffness in and around joint lasting at least 1 hour before maximal improvement
2. Arthritis of 3 or more of the following joints simultaneously: right or left PIP, MCP, wrist, elbow, knee, ankle, and MTP joints including soft tissue swelling or fluid
3. Arthritis of hand joint including swelling of wrist, MCP, or PIP joint
4. Symmetric involvement of joints on both sides of the body
5. Rheumatoid nodules over bony prominences, or extensor surfaces or in juxtaarticular regions
6. Positive abnormal serum rheumatoid factor
7. Radiographic changes including erosions or bony decalcification localized in or adjacent to the involved joints MTP = metatarsophalangeal; PIP = proximal interphalangeal; MCP = metacarpophalangeal joints.

As in the case patient described, the joints most often involved in RA are the PIP and MCP joints of the hands, wrists, shoulders, elbows, knees, ankles, and metatarsophalangeal (MTP) joints. The distal interphalangeal (DIP) joints are typically not affected, and the spine is not generally affected.[2,3] Questioning the patient about morning pain duration is important to gauge RA inflammatory activity; however, it may also be a feature of any inflammatory arthritis. Similar stiffness can occur after long periods of sitting or inactivity, whereas patients with degenerative arthritis have stiffness lasting just a few minutes.

Nonspecific, systemic RA symptoms frequently experienced include primarily fatigue, malaise, and depression. These may precede other symptoms of the disease by weeks to months. Patients most often complain of severe fatigue 4 to 6 hours after wakening. The symptoms may be accompanied by symptoms of anorexia. Functional limitations at work or home imposed by pain or fatigue should be investigated during the patient history. Low-grade fever occasionally occurs (temperature, 37° to 38°C; 99° to 100°F), but a higher fever suggests another illness, and infectious causes must then be considered. Atypical presentations of RA include intermittent joint inflammation that can be confused with gout or pseudogout, proximal muscle pain and tenderness mimicking polymyalgia rheumatica, or diffuse musculoskeletal pain seen in fibromyalgia.

(Adapted from Arnett FC, Edworthy SM, Bloch DA, et al. The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis. Arthritis Rheum. 1988,31:315-324. Used with permission.)