Asymptomatic or subclinical polyserositis

Specialty: General.

• silent serous inflammation
• multicavitary subclinical effusion
• accumulation of fluid in serous membranes

Why it occurs

• Systemic lupus erythematosus or mixed connective tissue disease (where the deposition of immune complexes in the pleura, pericardium and peritoneum causes low-grade inflammation and exudate)
• Generalized extrapulmonary tuberculosis (bacterial hematogenous seeding in serous membranes that induces a granulomatous inflammatory response)
• Severe hypothyroidism or myxedema (accumulation of mucopolysaccharides in the interstitial spaces of the serous membranes that attract water through an osmotic gradient)
• Late Dressler syndrome or post-cardiac injury polyserositis (autoimmune phenomenon against myocardial and pericardium antigens)
• Uremic nephropathy or nephrotic syndrome in the initial phases of solute retention and protein loss.

Initial workup

Multi-organ ultrasound (pleural, pericardial and abdominal to quantify the volume of effusions), acute phase reactants, antinuclear antibodies (ANA), anti-double-stranded DNA, serum complement levels (C3 and C4), TSH, and diagnostic thoracentesis or paracentesis if the fluid is accessible.

Standard management

• Colchicine — 0.5 mg orally once or twice a day to modulate the inflammatory response of serous membranes, with control of gastrointestinal effects
• Prednisone — 20 to 40 mg orally daily in a descending regimen if systemic autoimmune etiology is confirmed
• Indomethacin (25 to 50 mg orally every 8 hours as a non-steroidal anti-inflammatory with powerful action on serous membranes, with gastric protection).