(Discoid rash on the left, and malar rash on the right)
The American College of Rheumatology have criteria for diagnosing Systemic Lupus Erythematosis. You need 4 of the following to have a diagnosis, or 3 to have a 'probable' diagnosis.
- Malar Rash: erythema over the malar eminences that spares the nasolabial folds.
- Discoid Rash: raised patches with scaling. This may scar.
- Photosensitivity: a rash on skin exposed to sunlight.
- Oral Ulcerations: usually painless. See image below.
- Arthritis: this is nonerosive and involves 2 or more peripheral joints.
- Serositis: like pericarditis or pleuritis. You may hear a 'rub' on physical exam.
- Renal Disease: >0.5 grams of protein per day, or casts (red or heme granular).
- Neurologic Disease: seizures or psychosis, with other causes ruled out.
- Hematologic Disease: hemolytic anemia, thromocyotopenia, leukopenia, or lymphopenia.
- Antinuclear Antibody: positive titre in the absence of drugs known to cause a high titre (eg. procainamide, hydralazine).
- Immunologic Disorders: Antiphospholipid antibodies, or Anti ds-DNA antibodies, or anti Smith antibodies, or a false positive VDRL.