Lupus
Lupus, formally called systemic lupus erythematosus, is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms. Children up to 18 years old develop a more severe form of SLE termed childhood-onset systemic lupus erythematosus.
Lupus is Latin for "wolf": the disease was so-named in the 13th century as the rash was thought to resemble a wolf's bite.
The cause of SLE is not clear. It is thought to involve a combination of genetics and environmental factors. Among identical twins, if one is affected there is a 24% chance the other one will also develop the disease. Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections are also believed to increase a person's risk. The mechanism involves an immune response by autoantibodies against a person's own tissues. These are most commonly anti-nuclear antibodies and they result in inflammation. Diagnosis can be difficult and is based on a combination of symptoms and laboratory tests. There are a number of other kinds of lupus erythematosus including discoid lupus erythematosus, neonatal lupus, and subacute cutaneous lupus erythematosus.
There is no cure for SLE, but there are experimental and symptomatic treatments. Treatments may include NSAIDs, corticosteroids, immunosuppressants, hydroxychloroquine, and methotrexate. Although corticosteroids are rapidly effective, long-term use results in side effects. Alternative medicine has not been shown to affect the disease. Men have higher mortality. SLE significantly increases the risk of cardiovascular disease, with this being the most common cause of death. While women with lupus have higher-risk pregnancies, most are successful.
Rate of SLE varies between countries from 20 to 70 per 100,000. Women of childbearing age are affected about nine times more often than men. While it most commonly begins between the ages of 15 and 45, a wide range of ages can be affected. Those of African, Caribbean, and Chinese descent are at higher risk than those of European descent. Rates of disease in the developing world are unclear.
Signs and symptoms
SLE is one of several diseases known as "the great imitator" because it often mimics or is mistaken for other illnesses. SLE is a classical item in differential diagnosis, because SLE symptoms vary widely and come and go unpredictably. Diagnosis can thus be elusive, with some people having unexplained symptoms of SLE for years before a definitive diagnosis is reached.Common initial and chronic complaints include fever, malaise, joint pains, muscle pains, and fatigue. Because these symptoms are so often seen in association with other diseases, these signs and symptoms are not part of the diagnostic criteria for SLE. When occurring in conjunction with other signs and symptoms, however, they are considered suggestive.
While SLE can occur in both males and females, it is found far more often in women, and the symptoms associated with each sex are different. Females tend to have a greater number of relapses, a low white blood cell count, more arthritis, Raynaud syndrome, and psychiatric symptoms. Males tend to have more seizures, kidney disease, serositis, skin problems, and peripheral neuropathy.
Skin
As many as 70% of people with lupus have some skin symptoms. The three main categories of lesions are chronic cutaneous lupus, subacute cutaneous lupus, and acute cutaneous lupus. People with discoid lupus may exhibit thick, red scaly patches on the skin. Similarly, subacute cutaneous lupus manifests as red, scaly patches of skin but with distinct edges. Acute cutaneous lupus manifests as a rash. Some have the classic malar rash associated with the disease. This rash occurs in 30–60% of people with SLE.Hair loss, mouth and nasal ulcers, and lesions on the skin are other possible manifestations.
Muscles and bones
The most commonly sought medical attention is for joint pain, with the small joints of the hand and wrist usually affected, although all joints are at risk. More than 90 percent of those affected will experience joint or muscle pain at some time during the course of their illness. Unlike rheumatoid arthritis, lupus arthritis is less disabling and usually does not cause severe destruction of the joints. Fewer than ten percent of people with lupus arthritis will develop deformities of the hands and feet. People with SLE are at particular risk of developing osteoarticular tuberculosis.A possible association between rheumatoid arthritis and SLE has been suggested, and SLE may be associated with an increased risk of bone fractures in relatively young women.
Blood
is common in children with SLE and develops in about 50% of cases. Low platelet count and low white blood cell count may be due to the disease or a side effect of pharmacological treatment. People with SLE may have an association with antiphospholipid antibody syndrome, wherein autoantibodies to phospholipids are present in their serum. Abnormalities associated with antiphospholipid antibody syndrome include a paradoxical prolonged partial thromboplastin time and a positive test for antiphospholipid antibodies; the combination of such findings have earned the term "lupus anticoagulant-positive". Another autoantibody finding in SLE is the anti-cardiolipin antibody, which can cause a false positive test for syphilis.Heart
SLE may cause pericarditis, myocarditis, or endocarditis. The endocarditis of SLE is non-infectious, and is also called Libman–Sacks endocarditis. It involves either the mitral valve or the tricuspid valve. Atherosclerosis also occurs more often and advances more rapidly than in the general population.Steroids are sometimes prescribed as an anti-inflammatory treatment for lupus; however, they can increase one's risk for heart disease, high cholesterol, and atherosclerosis.
Lungs
SLE can cause pleuritic pain as well as inflammation of the pleurae known as pleurisy, which can rarely give rise to shrinking lung syndrome involving a reduced lung volume. Other associated lung conditions include pneumonitis, chronic diffuse interstitial lung disease, pulmonary hypertension, pulmonary emboli, and pulmonary hemorrhage.Kidneys
Painless passage of blood or protein in the urine may often be the only presenting sign of kidney involvement. Acute or chronic renal impairment may develop with lupus nephritis, leading to acute or end-stage kidney failure. Because of early recognition and management of SLE with immunosuppressive drugs or corticosteroids, end-stage renal failure occurs in less than 5% of cases, except in the black population, where the risk is many times higher.The histological hallmark of SLE is membranous glomerulonephritis with "wire loop" abnormalities. This finding is due to immune complex deposition along the glomerular basement membrane, leading to a typical granular appearance in immunofluorescence testing.
Neuropsychiatric
syndromes can result when SLE affects the central or peripheral nervous system. The American College of Rheumatology defines 19 neuropsychiatric syndromes in systemic lupus erythematosus. The diagnosis of neuropsychiatric syndromes concurrent with SLE, is one of the most difficult challenges in medicine, because it can involve so many different patterns of symptoms, some of which may be mistaken for signs of infectious disease or stroke.A common neurological disorder people with SLE have is headache, although the existence of a specific lupus headache and the optimal approach to headache in SLE cases remains controversial.
Other common neuropsychiatric manifestations of SLE include cognitive disorder, mood disorder, cerebrovascular disease, seizures, polyneuropathy, anxiety disorder, psychosis, depression, and in some extreme cases, personality disorders. Steroid psychosis can also occur as a result of treating the disease. It can rarely present with intracranial hypertension syndrome, characterized by an elevated intracranial pressure, papilledema, and headache with occasional abducens nerve paresis, absence of a space-occupying lesion or ventricular enlargement, and normal cerebrospinal fluid chemical and hematological constituents.
More rare manifestations are acute confusional state, Guillain–Barré syndrome, aseptic meningitis, autonomic disorder, demyelinating syndrome, mononeuropathy, movement disorder, myasthenia gravis, myelopathy, cranial neuropathy and plexopathy.
Neurological disorders contribute to a significant percentage of morbidity and mortality in people with lupus. As a result, the neural side of lupus is being studied in hopes of reducing morbidity and mortality rates. One aspect of this disease is severe damage to the epithelial cells of the blood–brain barrier. In certain regions, depression affects up to 60% of women with SLE.
Eyes
Up to one-third of patients report that their eyes are affected. The most common diseases are dry eye syndrome and secondary Sjögren's syndrome, but episcleritis, scleritis, retinopathy, ischemic optic neuropathy, retinal detachment, and secondary angle-closure glaucoma may occur. In addition, the medications used to treat SLE can cause eye disease: long-term glucocorticoid use can cause cataracts and secondary open-angle glaucoma, and long-term hydroxychloroquine treatment can cause vortex keratopathy and maculopathy.Reproductive
While most pregnancies have positive outcomes, there is a greater risk of adverse events occurring during pregnancy. SLE causes an increased rate of fetal death in utero and spontaneous abortion. The overall live-birth rate in people with SLE has been estimated to be 72%. Pregnancy outcome appears to be worse in people with SLE whose disease flares up during pregnancy.Neonatal lupus is the occurrence of SLE symptoms in an infant born from a mother with SLE, most commonly presenting with a rash resembling discoid lupus erythematosus, and sometimes with systemic abnormalities such as heart block or enlargement of the liver and spleen. Neonatal lupus is usually benign and self-limited.
Medications for treatment of SLE can carry severe risks for female and male reproduction. Cyclophosphamide can lead to infertility by causing premature ovarian insufficiency, the loss of normal function of one's ovaries prior to age forty. Methotrexate can cause termination or deformity in fetuses and is a common abortifacient, and for men taking a high dose and planning to father children, a discontinuation period of 6 months is recommended before insemination.