A 32-year-old Indian woman with SLE presents with joint pain, fever, and a new pericardial friction rub. Laboratory tests show elevated ESR, normal complement levels, and positive ANA with anti-dsDNA antibodies. Which of the following is NOT typically associated with SLE serositis?

## SLE Serositis — Clinical Manifestations and Complications **Key Point:** While SLE commonly causes acute serositis (pleurisy, pericarditis, peritonitis), **constrictive pericarditis as an initial presentation is NOT typical**. Constrictive pericarditis is a late, rare complication that develops after recurrent or chronic pericardial inflammation with fibrosis — it is not a primary manifestation of acute SLE serositis. ### Serositis in SLE — Typical Presentations | Serosal Site | Manifestation | Frequency | Characteristics | | --- | --- | --- | --- | | **Pleura** | Pleurisy ± effusion | 30–50% | Exudative, low complement, positive ANA/anti-dsDNA in fluid | | **Pericardium** | Acute pericarditis | 20–30% | Chest pain, friction rub, ST elevation; risk of tamponade | | **Peritoneum** | Lupus peritonitis | 5–10% | Abdominal pain, ascites, elevated peritoneal protein | | **Pericardium (late)** | Constrictive pericarditis | <1% | Rare, late complication after recurrent inflammation | **High-Yield:** The **ACR/EULAR 2019 criteria** include serositis (pleurisy or pericarditis) as a major clinical criterion, but constrictive pericarditis is NOT listed because it is a rare, late sequela, not an initial manifestation. **Clinical Pearl:** Acute SLE pericarditis may present with: - Pleuritic chest pain (worse with inspiration) - Pericardial friction rub - ECG changes (diffuse ST elevation, PR depression) - Risk of **pericardial tamponade** if large effusion develops Constrictive pericarditis, by contrast, develops after months to years of recurrent inflammation and fibrosis, presenting with signs of diastolic dysfunction (elevated JVP, Kussmaul sign, pulsus paradoxus). ### Why Constrictive Pericarditis is NOT a Typical Initial Presentation 1. **Pathogenesis:** Requires chronic, recurrent pericardial inflammation with progressive fibrosis — takes months to years to develop. 2. **Frequency:** Occurs in <1% of SLE patients; acute pericarditis is 20–30 times more common. 3. **Classification:** Acute serositis is a major criterion; constrictive pericarditis is a late complication, not part of initial SLE diagnosis. 4. **Clinical context:** Patients with acute SLE serositis present with inflammatory signs (fever, elevated ESR); constrictive physiology develops insidiously after inflammation resolves. [cite:Harrison 21e Ch 297]