Tests & Diagnosis
Due to the varied manifestations of lupus, and similarities of many symptoms with other systemic diseases, a classification system for lupus-specific diagnostic criteria has been developed. From a purely clinical perspective, patients who experience any four of the following 11 symptoms – simultaneously, or one after the other in any period of time – can be considered to have lupus:
- Malar rash, a red or purple-ish butterfly-shaped facial rash around the cheeks and bridge of the nose, but typically not involving the folds extending out from the nostrils towards the mouth
- Discoid rash, a series of chronic, raised, inflamed sores that usually affect the face, ears and scalp
- Photosensitivity, rash-like reactions to sunlight
- Oral ulcers, (typically) painless breaks in the skin on the inside of the mouth and throat
- Arthritis, in the form of tenderness, swelling or fluid build-up, involving two or more peripheral joints, such as shoulder, elbow, wrist, knee or ankle. Occasionally, changes to ligaments and bone deformities can occur but, in contrast to the erosion and destruction found in rheumatoid arthritis, they are usually reversible.
- Serositis, or inflammation of the lining of the lungs, heart, or abdomen and abdominal organs.
- Kidney disorders
- Neurological disorder such as seizures or psychosis, without the presence of drugs or other metabolic imbalances.
- Blood disorders leukopenia, lymphopenia, thrombocytopenia, or a specific form of anemia
- Specific immunologic disorders
- An abnormal measure of antinuclear antibody (ANA)
It is important to note that while this classification system is used for clinical studies, it is not the final word on diagnosis; it is often assumed, for example, that a patient with the characteristic malar rash and elevated ANA test results has lupus, even though they comprise just two of the 11 criteria; consult with your physician on testing and diagnosis.
Lupus must be diagnosed clinically, based in part on these specific signs and symptoms; the following differential diagnoses must be ruled out due to their similarity with the symptoms of lupus:
- Acute Pericarditis
- Antiphospholipid Syndrome
- Autoimmune Hepatobilliary Disease
- Hepatitis C
- Infectious Mononucleosis (‘mono’)
- Infective Endocarditis
- Lyme Disease
- Mixed connective tissue disease
- Rheumatoid Arthritis
- Sjogren Syndrome