RA and Lupus Diagnosis Criteria

Lately I've heard some strange stories from friends who were told they couldn't have Lupus or RA for various reason. One friend was told she didn't have Lupus because she didn't have psychosis or seizures. 

With all of the misinformation floating around, I thought I would share the diagnosis criteria for each of these diseases.

Rheumatoid Arthritis:

 At least four of the following criteria must be met in order to diagnose a patient with RA

1. Morning stiffness or stiffness after sitting for a prolonged period that lasts at least one hour and has been present for at least six weeks.
2. Swelling of three or more joints for at least six weeks.
3. At least one swollen area in the wrist, hand, or fingers
4. Symmetrical joint swelling
5. Presence of rheumatoid nodules
6. Abnormal Rheumatoid Factor levels in the blood
7. X-ray changes in the hands - although this is now thought to be evident only in disease progression.

Lupus:

 Any combination of four of the following eleven criteria are a good indication the patient may have Lupus:

1. Rash - fixed redness either flat or raised over the nose and cheeks
2. Discoid rash - red, circular raised patches with scaling, hair follicle plugging and possible scaring.
3. Photosensitivity - exposure to sun or ultraviolet light causes the rash.
4. Oral and nasopharangyeal ulcers
5. Arthritis of two or more joints with tenderness and swelling
6. Pleuritis, pericarditis or serositis
7. Renal disorder with protein >0.5g/d or 3+ cellular casts in urine
8. Neurologic disorder: either seizures or psychosis without other causes
9. Hematologic disorder - either hemolytic anemia, leukopenia, lymphopenia, or thrombocytopenia without a drug-induced cause.
10. Immunologic disorder - Anti-dsDNA, anti-SM, and/or anti-phospholipid
11. Antinuclear antibodies: An abnormal ANA titer in absence of drugs known to induce.

1.  http://www.medicalcriteria.com/criteria/sle.htm
2. http://www.webmd.com/rheumatoid-arthritis/guide/diagnosing-ra