creation date: 2026-02-05 21:11
tags: PathologiesIncomplete
Systemic Lupus Erythematosus
Background
Definitions
Systemic lupus erythematosus (SLE) is a chronic, multisystem autoimmune disease.
Lupus is most common in younger to middle-aged females.
Etiology and Pathogenesis
The pathogenesis of SLE is unknown but multifactorial. A number of abnormalities of the immune system, genetics, environmental, and hormonal risk factors results in autoantibody production.
Generally, a genetically susceptible individual may activate autoimmunity from exposure to environmental factors. The autoimmunity and thus self-targeted immune response results in cytokine release, complement activation, inflammation, and organ damage.
Further deficiencies in neutralization of autoreactive immunity results in a positive feedback loop of self-activating B and T cells which further worsen autoimmunity.
Clinical Presentation
Signs & Symptoms
Clinical manifestation can vary significantly. The symptoms experienced can fluctuate in intensity and change in type as well.
Constitutional symptoms
Common in most patients at some point in the disease course.
- Fatigue
- Fever
- Myalgia and muscle weakness
- Weight change (decrease may be due to decreased appetite, GI disease; increase may be due to water retention from hypoalbuminemia)
Arthritis and arthralgias
One of the earliest manifestations. Tends to be:
- Migratory, polyarticular, symmetrical
- Associated with inflammation
- Painful
- Not erosive and rarely deforming
Mucocutaneous
Skin and mucous membrane lesions may manifest at some point during disease course.
- Facial eruption (“butterfly rash”) - malar distribution over cheeks and nose but spares nasolabial folds
- Discoid lesions (inflammatory and tendency to scar)
- Oral and/or nasal ulcers
Lesions are associated with:
- Photosensitivity
Cardiac and vascular
- Pericarditis (with or without effusion)
- Endocarditis (often clinically silent but may produce valvular insufficiency)
- Increased risk of coronary artery disease
- Raynaud phenomenon
- Vasculitis
- Thromboembolic disease
Kidneys
Kidney involvement can occur in 50% of patients. This is referred to as lupus nephritis which can manifest as:
- Abnormal urinalysis (eg. microscopic hematuria, proteinuria)
- Elevated plasma creatinine
- Hypertension
Gastrointestinal
Most GI symptoms are related to:
- Medication
- Viral/bacterial infection
Manifestations include:
- Esophageal motility disorders
- Peptic ulcer disease
- Intestinal pseudo-obstruction (obstructive symptoms without anatomic lesion)
- Autoimmune hepatitis (active hepatitis with circulating ANA and/or ASMA)
- Lupus hepatitis (insidious elevation of aminotransferase with nonspecific symptoms)
- Acute pancreatitis
- Mesenteric vasculitis/ischemia
- Peritonitis and ascites (rare)
Pulmonary
- Pleuritis with or without effusion
- Pneumonitis
- Interstitial lung disease
- Pulmonary hypertension
- Shrinking lung syndrome
- Alveolar hemorrhage
Neurologic and neuropsychiatric
Neurologic manifestations include:
- Stroke
- Seizures
- Cognitive dysfunction
- Delirium
- Psychosis
- Peripheral neuropathies
Hematologic
All blood cell lines can be affected.
- Anemia of chronic disease
- Leukopenia (driven by lymphopenia)
- Neutropenia
- Thrombocytopenia
Lymph node enlargement may occur in the cervical, axillary, and inguinal regions.
Ophthalmologic
Structures of the eye can be involved with findings including:
- Pain
- Proptosis
- Lid swelling
- Diplopia
Other associated conditions
- Immunodeficiencies
- Antiphospholipid syndrome
- Fibromyalgia
- Osteonecrosis
- Osteoporosis
- Infection risk
History & Physical Exam
A thorough medical history is warranted to assess for presence of signs and symptoms characteristic of SLE. Note that some clinical features are more common at disease onset (particularly fatigue, arthralgias, and skin manifestations).
A complete physical exam is indicated due to multiorgan involvement.
Diagnosis
Criteria
Work-up
Laboratory testing when suspecting SLE
- CBC with differential
- Basic metabolic panel and LFTs
- Creatine kinase
- Urinalysis including urine sediment and urine protein-to-creatinine
- Serum protein electrophoresis
- ANA
- Extractable nuclear antigen panel
- Anti-dsDNA
- Antiphospholipid antibodies
- C3 and C4 or CH50 complement levels
- ESR and/or CRP
- TSH and anti-thyroid antibodies
Imaging
Imaging is not routine unless clinical findings include swollen joints/MSK, renal manifestations, cardiac manifestations etc.
Imaging includes plain radiographs, ultrasounds, and CTs.