Snapshot A 46-year-old African American woman with history of systemic lupus erythematosus presents with increasing fatigue, arthralgias, rash, and hematuria. She reports that she had previously been on hydroxychloroquine with success but had not seen a physician in 5 years. Physical exam shows a malar rash on her face. Laboratory exam reveals a highly positive antinuclear, anti-double-stranded DNA, and anti-Smith antibodies. She also has low complement levels. She is restarted on hydroxychloroquine and steroids. Introduction Clinical definition systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by acute flares, commonly presenting with rash, joint pain, and fever multiple organ systems are involved, including renal, neurologic, dermatologic, cardiovascular, and hematologic Epidemiology Demographics more common in female patients of reproductive age African American, Asian, or Hispanic descent Risk factors family history oral contraceptive use hormone replacement therapy other autoimmune diseases ETIOLOGY Pathogenesis unknown but thought to be an interaction among immune dysfunction, genetic factors, and environmental factors autoantibodies precipitate immune complexes in multiple organs, including kidneys, skin, and brain polyclonal activation of B cells with the production of autoantibodies against DNA complement factors and cytokines also play a key role environmental triggers include sunlight (photosensitive rash), infection, and drugs login to view 3 more bullets Associated conditions antiphospholipid syndrome increased risk of thrombosis increased risk of atherosclerosis lupus nephritis anti-DNA immune complexes deposition in glomeruli nephritic or nephrotic syndrome login to view 1 more bullet drug-induced lupus typically positive for antinuclear and antihistone antibodies typically without renal or neurologic involvement complement level is typically normally Libman-Sacks endocarditis (LSE) noninfectious endocarditis characterized by thrombi on the mitral or aortic valves (LSE in SLE) Raynaud phenomenon neonatal lupus erythematosus associated with patients with anti-Ro or anti-La antibodies neonates present with rashes and congenital heart block Presentation Symptoms constitutional symptoms fatigue, fever, or weight loss arthralgias serositis pericarditis, pleural effusion, or myocarditis Physical exam cutaneous findings malar rash (raised or flat erythematous butterfly rash on cheeks/nose and spares nasolabial fold) discoid lesions (erythematous raised plaques with keratotic scale and follicular plugging) photosensitive rash oral ulcers neurologic findings behavioral changes stroke seizures headaches chance in psychiatric status renal findings hematuria proteinuria Studies Labs antibodies antinuclear antibody (ANA) login to view 2 more bullets anti-double-stranded DNA (dsDNA) antibody login to view 4 more bullets anti-Smith antibody (antibody to snRNPs) login to view 1 more bullet anti-Ro and anti-La login to view 2 more bullets antihistone antibody login to view 1 more bullet ↓ complement levels during a flare ↓C3, C4, and CH50 ↑ erythrocyte sedimentation rate pancytopenia leukopenia, thrombocytopenia, or hemolytic anemia caused by immune-mediated destruction elevated partial thromboplastin time (PTT) lupus anticoagulant increases the risk for thrombi and miscarriages associated with antiphospholipid syndrome Urinalysis proteinuria or hematuria may indicate renal disease Differential Acne rosacea distinguishing factors erythematous papules and pustules on face without nasolabial sparing no other systemic findings Sarcoidosis distinguishing factors adenopathy restrictive lung disease skin findings of lupus pernio, rather than malar rash, discoid lesions, or ulcers DIAGNOSIS Making the diagnosis based on clinical presentation and laboratory studies diagnosis confirmed with 4 or more criteria from RASHNIA4 Renal disease Arthralgias Serositis Hematologic abnormalities Neurologic abnormalities Immunologic derangements Antinuclear antibodies 4 types of rashes login to view 4 more bullets Treatment Management approach antimalarials are often used alongside steroids for acute flares management is often dictated by specific organ involvement Conservative use sunscreen and avoid sun exposure indications login to view 1 more bullet Medical non-steroidal anti-inflammatory drugs (NSAIDs) indications login to view 1 more bullet antimalarials indications login to view 2 more bullets drugs login to view 2 more bullets side effects login to view 1 more bullet steroids indications login to view 1 more bullet drugs login to view 1 more bullet immunosuppressants indications login to view 3 more bullets drugs login to view 6 more bullets belimumab indications login to view 1 more bullet mechanism login to view 1 more bullet Complications Causes of death in SLE infections renal disease cardiovascular disease leading cause of death in these patients includes Libman-Sacks endocarditis, hypertension, and cardiac tamponade Thrombosis Prognosis Often have recurrent flares