The diagnosis of SLE is made based on a combination of symptoms, signs and test results and after other illnesses have been ruled out. There is no single disease symptom, sign or test which, alone, will give a diagnosis of SLE. Given the thousand faces of SLE, and because symptoms such as fatigue, weight loss or fever may be the only clues at the beginning, the diagnosis may be especially difficult. However, physicians are more aware of this situation and the result is shorter delays in diagnosis and the recognition of milder forms of lupus.
Four, and sometimes five, steps are needed to establish the diagnosis. The first is a thorough review of the person’s symptoms. The second is a detailed physical examination. The third is performance of a whole battery of tests. Remember that several of the 11 SLE criteria consist of abnormal laboratory tests and it is just not possible to avoid doing all those tests (and taking all that blood) because it is not known what tests will be abnormal in a given person. Furthermore, some patients may experience only one or two minor symptoms, while several abnormal tests will help to make the diagnosis. There is no shortcut in this process.
The fourth step is to rule out other diseases which may have symptoms or test abnormalities in common with SLE such as rheumatoid arthritis, scleroderma, mixed connective tissue disease, Sjögren’s syndrome, and many other ailments. It is as important to identify those who do not have SLE as it is to find those who do. The fifth step that is sometimes necessary is time. Fewer than four criteria or conditions may be present at the time that symptoms first appear and, while the doctor may suspect SLE, the diagnosis is not yet absolutely clear. As SLE may sometimes unveil slowly, a long period of careful observation may be necessary.
Finally, there is another procedure that may be very useful in making a diagnosis. A biopsy (the removal of a small piece of tissue) of the skin or of one kidney is often performed. A skin biopsy may help to make a diagnosis of skin vasculitis, of discoid or subacute lupus or of the lupus nature of various skin rashes. A kidney biopsy provides valuable information on the type, the degree and the age of lupus lesions and is very helpful in choosing the right treatment.
Once a diagnosis of lupus is made, the patient’s symptoms will be treated if necessary. The goal of any treatment is to bring the symptoms and the disease under control so that the patient can lead as normal a life as possible. Patients will be reassured to learn that a variety of treatments are available and that physicians use great care in deciding which treatment is best.