-IBIS-1.5.0-
tx
immune system
systemic lupus erythematosus
diagnoses

definition and etiology

definition: An inflammatory autoimmune connective tissue disorder.

etiology: The cause is unknown. SLE is seen mainly in young women aged 20-40 (90% of cases), but in 10% of the cases the patient is a child or a senior citizen.

signs and symptoms

SLE may have an acute or gradual onset.

• Skin: "Butterfly rash" plus other discoid skin lesions; worse sunlight; oral lesions/ulcers.
• Fatigue, malaise, fever, anorexia, nausea, weight loss.
• Arthralgias and/or myalgias.
• Anemia, leukopenia, lymphopenia.
• Pleurisy, pericarditis.
• Proteinuria, cellular casts.
• Ascites.
• Many other possible symptoms based on the organ system involved (which may be any).

lab findings:
• (+) LE cells (60%)
• (+) ANA (FANA detects 95%, best test)
• (+) Anti-DNA antibodies in 40-80% of cases
• Increased ESR reflecting disease activity
• false (+) VDRL
• (+) anti-ENA (anti-RNP, anti-Sm)
• (+) lupus band test done on skin biopsy
• anemia of chronic disease, or occasionally hemolytic
• leukocytopenia reflects disease activity
• decreased C3C4 (complement fractions) and C1q binding
• circulating immune complexes reflect disease activity

course and prognosis

The prognosis varies with organs involved and degree of severity. Patients with kidney or cardiac involvement have a poorer prognosis that those whose condition is limited to joints, skin, and serous membranes. SLE is characterized by exacerbations and remissions, although long-lasting remissions are only seen in 10% of patients. The mortality rate is 5%/year.

differential diagnosis

• Discoid LE.
• Other connective tissue or auto-immune diseases.
• Systemic nodular panniculitis.


footnotes