What is systemic lupus erythematosus?

Systemic lupus erythematosus is a chronic, degenerative autoimmune disorder characterized by inflammation that can affect the skin, joints, kidneys, lungs, nervous system and other organs. Symptoms can be moderate to severe and may occur in episodes of flare-ups followed by temporary remission.

Symptoms vary greatly among patients and may begin with fever or infection. Systemic lupus erythematosus (SLE) can be difficult to diagnose because many symptoms mimic those of other illnesses such as fatigue, chest pain, mild to severe headaches, fever with no other cause, general malaise and swollen lymph glands.

Some patients may experience arthralgias, acute polyarthritis, usually intermittently, before other symptoms present. A malar facial rash is common but may not present in all patients. Mottled red areas may appear on the sides of the palms and fingers. Swelling in joints, around the nails and purple blotches may appear at the inner knuckles.

Heart problems can develop, and chest pain may occur due to pericarditis. A patient may experience arrhythmias, and less commonly, coronary artery vasculitis may develop leading to angina, myocarditis or heart valve damage.

In about 10% of SLE patients, the spleen becomes enlarged. Some patients develop mild to severe kidney problems which can be fatal. Early symptoms of kidney problems include swelling and weight gain.

In addition to nausea, diarrhea and general abdominal discomfort, other more serious gastrointestinal problems may develop due to reduction of blood flow to the gastrointestinal tract, including perforations. Damage to the liver and pancreatitis can also occur.

Changes to the brain can also occur, and symptoms include numbness, tingling, vision problems, seizures, epilepsy and personality changes.

The cause of SLE is unknown. In some cases it is caused by particular drugs, such as hydralazine, procainamide and isoniazid. Drug-induced SLE usually subsides once treatment is discontinued.

About 70% to 90% of people who develop SLE are women of child-bearing age, but onset can occur in newborns, children and older adults. It is more common in blacks and Asians and SLE can manifest in different forms. In discoid lupus erythematosus, only the skin is affected. Raised, round rashes appear which can progress and cause skin loss, scarring, and loss of hair in the area. The rashes usually occur on areas of the skin that are exposed to light.

Some patients with discoid lupus erythematosus will develop rashes or sores in mucous membranes, particularly in the mouth, which can be general symptoms of SLE. About 10% of patients with discoid lupus erythematosus will exhibit more serious symptoms of SLE in the joints, kidneys and brain.

Subacute cutaneous lupus erythematosus also mostly affects the skin. In this form, rashes are more widespread, commonly recurring and may get worse when exposed to sunlight, but scarring rarely occurs. Rashes are usually on the face, arms and trunk, and patients may experience fatigue and joint pain, but usually not the more detrimental effects of SLE.

In addition to the use of the System Lupus International Collaborating Clinics /American College of Rheumatology Damage Index, levels of antinuclear antibodies, anti-dsDNA, anti-Sm and antiphospholipid antibodies can help confirm a diagnosis of SLE, but the levels of antibodies may not be proportional to disease activity.

References:

http://www.nlm.nih.gov/medlineplus/ency/article/000435.htm

http://www.mayoclinic.org/diseases-conditions/lupus/basics/definition/con-20019676

https://www.rheumatology.org/practice/clinical/patients/diseases_and_conditions/lupus.asp