Lupus Flashcards
SLE symptoms?
SLE is one of several diseases known as “the great imitator” because it often mimics or is mistaken for other illnesses.[9] SLE is a classical item in differential diagnosis,[10] 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.
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 (see below), however, they are considered suggestive.[11]
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.[5] Females tend to have a greater number of relapses, a low white blood cell count, more arthritis, Raynaud’s phenomenon, and psychiatric symptoms. Males tend to have more seizures, kidney disease, serositis (inflammation of tissues lining the lungs and heart), skin problems, and peripheral neuropathy.[12]
Skin
As many as 70% of people with lupus have some skin symptoms. The three main categories of lesions are chronic cutaneous (discoid) 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 (or butterfly rash) associated with the disease.[13] This rash occurs in 30 to 60% of people with SLE.[14]
Hair loss, mouth and nasal ulcers, and lesions on the skin are other possible manifestations.[15]
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.[16] 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.[16] People with SLE are at particular risk of developing osteoarticular tuberculosis.[17]
A possible association between rheumatoid arthritis and SLE has been suggested,[18] and SLE may be associated with an increased risk of bone fractures in relatively young women
Blood
Anemia is common in children with SLE[20] and develops in about 50% of cases.[21] Low platelet and white blood cell counts may be due to the disease or a side effect of pharmacological treatment. People with SLE may have an association with antiphospholipid antibody syndrome[22] (a thrombotic disorder), wherein autoantibodies to phospholipids are present in their serum
Heart
SLE may cause pericarditis—inflammation of the outer lining surrounding the heart, myocarditis—inflammation of the heart muscle, or endocarditis—inflammation of the inner lining of the heart.
Lungs
Inflammation of the pleurae known as pleurisy can rarely give rise to shrinking lung syndrome.[25] SLE can cause pleuritic pain and also give rise to shrinking lung syndrome, involving a reduced lung volume.
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, end-stage renal failure occurs in less than 5%[27][28] 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.[29] This finding is due to immune complex deposition along the glomerular basement membrane, leading to a typical granular appearance in immunofluorescence testing.
A common neurological disorder people with SLE have is headache,[33] although the existence of a specific lupus headache and the optimal approach to headache in SLE cases remains controversial.[34] Other common neuropsychiatric manifestations of SLE include cognitive dysfunction, mood disorder, cerebrovascular disease,[33] seizures, polyneuropathy,[33] anxiety disorder, psychosis, depression, and in some extreme cases, personality disorders.
SLE Causes?
SLE is presumably caused by a genetic susceptibility coupled with an environmental trigger which results in defects in the immune system. One of the factors associated with SLE is vitamin D deficiency.[44
Drug reactions
Drug-induced lupus erythematosus is a (generally) reversible condition that usually occurs in people being treated for a long-term illness. Drug-induced lupus mimics SLE. However, symptoms of drug-induced lupus generally disappear once the medication that triggered the episode is stopped. More than 38 medications can cause this condition, the most common of which are procainamide, isoniazid, hydralazine, quinidine, and phenytoin.[54][10]
Non-systemic forms of lupus
Discoid (cutaneous) lupus is limited to skin symptoms and is diagnosed by biopsy of rash on the face, neck, scalp or arms. Approximately 5% of people with DLE progress to SLE
SLE Pathophysiology?
ne manifestation of SLE is abnormalities in apoptosis, a type of programmed cell death in which aging or damaged cells are neatly disposed of as a part of normal growth or functioning.
In SLE, the body’s immune system produces antibodies against itself, particularly against proteins in the cell nucleus. SLE is triggered by environmental factors that are unknown.
SLE Diagnosis
Antinuclear antibody (ANA) testing and anti-extractable nuclear antigen (anti-ENA) form the mainstay of serologic testing for SLE. Several techniques are used to detect ANAs. Clinically the most widely used method is indirect immunofluorescence
Other tests routinely performed in suspected SLE are complement system levels (low levels suggest consumption by the immune system), electrolytes and kidney function (disturbed if the kidney is involved), liver enzymes, and complete blood count.
The American College of Rheumatology (ACR) established eleven criteria in 1982,[73] which were revised in 1997[74] as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individuals and do not do well in that capacity. For the purpose of identifying people for clinical studies, a person has SLE if any 4 out of 11 symptoms are present simultaneously or serially on two separate occasions.
Malar rash (rash on cheeks); sensitivity = 57%; specificity = 96%.[75] Discoid rash (red, scaly patches on skin that cause scarring); sensitivity = 18%; specificity = 99%.[75] Serositis: Pleurisy (inflammation of the membrane around the lungs) or pericarditis (inflammation of the membrane around the heart); sensitivity = 56%; specificity = 86% (pleural is more sensitive; cardiac is more specific).[75] Oral ulcers (includes oral or nasopharyngeal ulcers); sensitivity = 27%; specificity = 96%.[75] Arthritis: nonerosive arthritis of two or more peripheral joints, with tenderness, swelling, or effusion; sensitivity = 86%; specificity = 37%.[75] Photosensitivity (exposure to ultraviolet light causes rash, or other symptoms of SLE flareups); sensitivity = 43%; specificity = 96%.[75] Blood—hematologic disorder—hemolytic anemia (low red blood cell count), leukopenia (white blood cell count<4000/µl), lymphopenia (<1500/µl), or low platelet count (<100000/µl) in the absence of offending drug; sensitivity = 59%; specificity = 89%.[75] Hypocomplementemia is also seen, due to either consumption of C3[76] and C4 by immune complex-induced inflammation or to congenitally complement deficiency, which may predispose to SLE. Renal disorder: More than 0.5 g per day protein in urine or cellular casts seen in urine under a microscope; sensitivity = 51%; specificity = 94%.[75] Antinuclear antibody test positive; sensitivity = 99%; specificity = 49%.[75] Immunologic disorder: Positive anti-Smith, anti-ds DNA, antiphospholipid antibody, or false positive serological test for syphilis; sensitivity = 85%; specificity = 93%.[75] Presence of anti-ss DNA in 70% of cases (though also positive with rheumatic disease and healthy persons).[77] Neurologic disorder: Seizures or psychosis; sensitivity = 20%; specificity = 98%.[75] Other than the ACR criteria, people with lupus may also have:[78]
fever (over 100 °F/ 37.7 °C)
extreme fatigue
hair loss
fingers turning white or blue when cold (Raynaud’s phenomenon)
SLE treatment?
Treatment can include corticosteroids and anti-malarial drugs. Certain types of lupus nephritis such as diffuse proliferative glomerulonephritis require intermittent cytotoxic drugs. These drugs include cyclophosphamide and mycophenolate.
Lifestyle changes
Avoiding sunlight in SLE is critical, since sunlight is known to exacerbate skin manifestations of the disease. Avoiding activities which induce fatigue is also important, since those with SLE fatigue easily and it can debilitating. These two problems can lead to people becoming housebound for long periods of time. Drugs unrelated to SLE should be prescribed only when known not to exacerbate the disease. Occupational exposure to silica, pesticides, and mercury can also worsen the disease.[60]
SLE Prognosis
No cure is available for SLE but there are many treatments for the disease.[1]
In the 1950s, most people diagnosed with SLE lived fewer than five years. Today, over 90% now survive for more than ten years, and many live relatively symptom-free. 80–90% can expect to live a normal lifespan.[93] Mortality rates are however elevated compared to people without SLE.[94]
Prognosis is typically worse for men and children than for women; however, if symptoms are present after age 60, the disease tends to run a more benign course. Early mortality, within 5 years, is due to organ failure or overwhelming infections, both of which can be altered by early diagnosis and treatment. The mortality risk is fivefold when compared to the normal population in the late stages, which can be attributed to cardiovascular disease from accelerated atherosclerosis, the leading cause of death for people with SLE.[83] To reduce the potential for cardiovascular issues, high blood pressure and high cholesterol should be prevented or treated aggressively. Steroids should be used at the lowest dose for the shortest possible period, and other drugs that can reduce symptoms should be used whenever possible.[83]
SLE Epidemiology?
The global rates of SLE are approximately 20–70 per 100,000 people. In females, the rate is highest between 45 and 64 years of age. The lowest overall rate exists in Iceland and Japan. The highest rates exist in the US and France. However, there is not sufficient evidence to conclude why SLE is less common in some countries compared to others; it could be the environmental variability in these countries. For example, different countries receive different levels of sunlight, and exposure to UV rays affects dermatological symptoms of SLE. Certain studies hypothesize that a genetic connection exists between race and lupus which affects disease prevalence. If this is true, the racial composition of countries affects disease, and will cause the incidence in a country to change as the racial makeup changes. In order to understand if this is true, countries with largely homogenous and racially stable populations should be studied to better understand incidence.[2] Rates of disease in the developing world are unclear.[6]
The rate of SLE varies between countries, ethnicity, and sex, and changes over time.[95] In the United States, one estimate of the rate of SLE is 53 per 100,000;[95] other estimates range from 322,000 to over 1 million.[96] In Northern Europe the rate is about 40 per 100,000 people.[97] SLE occurs more frequently and with greater severity among those of non-European descent.[96] That rate has been found to be as high as 159 per 100,000 among those of Afro-Caribbean descent.[95] Childhood-onset systemic lupus erythematosus generally presents between the ages of 3 and 15 and is four times more common in girls.[98]
While the onset and persistence of SLE can show disparities between genders, socioeconomic status also plays a major role. Women with SLE and of lower socioeconomic status have been shown to have higher depression scores, higher body mass index, and more restricted access to medical care than women of higher socioeconomic statuses with the illness. People with SLE had more self-reported anxiety and depression scores if they were from a lower socioeconomic status.[99]
