Systemic Lupus Erythematosus (SLE) Differential Diagnoses

Updated: Nov 11, 2022
  • Author: Christie M Bartels, MD, MS; Chief Editor: Herbert S Diamond, MD  more...
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DDx

Diagnostic Considerations

Before making a diagnosis of systemic lupus erythematosus (SLE), ruling out drugs as the cause of the condition is important. Many pharmacologic agents have been associated with a lupuslike syndrome (see Drug-Induced Lupus Erythematosus), but procainamide, hydralazine, and isoniazid have been studied the most extensively. Many patients who take these medications have positive antinuclear antibody test results and other serologic findings. Only a few have the clinical manifestations. Drug-induced lupus differs from SLE by the following features:

  • Sex ratios are nearly equal
  • Antibodies to histones are usually found in 80-90%
  • Nephritis and central nervous system features are not commonly present
  • There are no antibodies to native DNA or hypocomplementemia
  • Discontinuation of the drug leads to resolution of clinical manifestations and reversion of abnormal laboratory values to normal

A syndrome of drug-induced SLE has been observed with minocycline and propylthiouracil. Both drugs have a decreased frequency of antihistone antibodies and anti–double-stranded DNA antibodies, and results for antineutrophil cytoplasmic antibodies are sometimes positive. Anti-TNF drugs are reported to cause severe drug-induced lupus, including production of many SLE autoantibodies and, rarely, even nephritis. [111]

Other problems to be considered in the differential diagnosis of SLE include the following:

  • Discoid skin lesions
  • Erythematous macules
  • Interstitial lung disease
  • Leukemia
  • Leukopenia
  • Parvovirus or other viral infections
  • Photodistributed rash
  • Pleuritic chest pain
  • Pneumonitis
  • Polyarthritis/polyarthralgia
  • Renal vasculitis
  • Seizures
  • Stroke
  • Thrombocytopenia
  • Vasculitis

Differential Diagnoses