I will occasionally have a patient who suffers from fatigue and joint pains ask as to whether they might have lupus. For those not familiar with this disease, lupus is one of numerous autoimmune diseases that can affect people. Autoimmune diseases are a family of illnesses where our immune system, which normally exists to fight germs, goes haywire and in turn attacks different parts of the body. Systemic lupus can be particularly serious and debilitating because of the many organ systems that can be involved. In fact, diagnosing somebody with lupus requires having several symptoms involving different body parts.
The American College of Rheumatology established criteria for diagnosing lupus back in 1982 and revised them in 1997. There are a total of 11 criteria and a patient should fulfill at least four of them to be considered to have lupus. Three of the criteria involve distinct skin conditions. One skin condition is the classic “butterfly” or malar rash that can appear on the face while another is a thick scaly rash called a discoid rash. The other skin condition is one called photosensitivity, where a skin rash forms in reaction to sunlight exposure. Another criterion involves the presence of internal ulcers found in the mouth and/or the nose. Arthritis is also a feature of lupus. Unlike autoimmune diseases like rheumatoid arthritis, where the joint inflammation causes pieces of the bone to wear away, bone destruction is usually not seen with lupus. However, this doesn’t mean that arthritis pain in lupus isn’t significant nor that it can’t be deforming. Arthritis pain in lupus, as in other autoimmune disease, is often worse earlier in the day. Not only can inflammation in lupus occur in the joints to cause arthritis, but it can also occur in the lining of the lungs (also called pleuritis) or the sac lining the heart (also called pericarditis). Inflammation in these organs not only leads to chest pain, but can lead to complications that cause difficulty with heart and lung function. Besides the heart and lungs, lupus can also affect the kidneys and lead to kidney failure if untreated with strong medicines. One underappreciated feature of lupus is its effect on the brain and mind. Problems from seizures to psychotic behavior to paralysis have been seen in lupus. Lupus can also go on to affect the function of the bone marrow and many patients will suffer low white blood cell counts, red blood cell counts and platelets. The last two criteria relate to the presence of positive antibodies that can be found in the blood of lupus sufferers. The tricky part of these criteria is that some are very common in lupus but are not specific for lupus. That is, somebody can have a positive antibody test and not necessarily have lupus. On the other hand, not having any positive antibody blood tests doesn’t mean that one doesn’t have lupus. This is where paying attention to the other criteria is important. Systemic lupus can indeed be tricky to diagnose in a patient, often requiring referral to a specialist in order to help clear up whether they truly have the disease or not. If you suspect having a condition like this, I encourage you to have a dialogue with your primary care provider regarding your concerns.