Differential Diagnosis for Lupus in Pregnancy

Given the presentation of fever, generalized pain, and a history of eclampsia, with all urine and respiratory etiologies ruled out, the differential diagnosis can be organized into the following categories:

• Single Most Likely Diagnosis
  • Systemic Lupus Erythematosus (SLE) flare: This is a likely diagnosis given the symptoms of fever and generalized pain, especially in the context of a history that could suggest an autoimmune predisposition (eclampsia has been associated with autoimmune disorders in some cases). SLE can present for the first time during pregnancy and can be triggered by pregnancy itself.
• Other Likely Diagnoses
  • Preeclampsia: Although the patient has a history of eclampsia, preeclampsia can recur in subsequent pregnancies and may present with systemic symptoms including pain and fever, especially if there is significant end-organ involvement.
  • Intrauterine infection (e.g., chorioamnionitis): This condition can cause fever and generalized pain, and while urine and respiratory etiologies have been ruled out, an intrauterine source of infection should be considered, especially if there are other symptoms such as uterine tenderness or fetal distress.
• Do Not Miss Diagnoses
  • Placenta accreta spectrum disorders: These conditions can cause significant maternal morbidity and mortality and may present with pain and possibly fever if there is associated infection or placental abruption.
  • HELLP syndrome: A variant of preeclampsia, characterized by Hemolysis, Elevated Liver enzymes, and Low Platelet count, which can present with fever, pain, and may mimic other conditions.
• Rare Diagnoses
  • Thrombotic thrombocytopenic purpura (TTP) or Hemolytic-uremic syndrome (HUS): These are rare conditions that can present with systemic symptoms including fever and pain, and are associated with significant morbidity and mortality if not promptly diagnosed and treated.
  • Antiphospholipid syndrome (APS): This condition can cause a variety of symptoms including thrombosis, fetal loss, and systemic symptoms, and may be considered in the differential diagnosis of a pregnant patient with a history suggestive of autoimmune disease.

Each of these diagnoses requires careful consideration and further evaluation based on the patient's specific presentation, laboratory findings, and imaging studies as appropriate.