The third part of the diagnostic triad looking at patients with dyspnea and swollen ankles is nephrotic syndrome. It is a chronic disease that affects the basement membrane of the glomerulus in the kidney. The cause of nephrotic syndrome is mostly unknown, but it has been linked to diseases like diabetes and systemic lupus erythematosus, certain drugs, and certain infections such as malaria.
A patient with nephrotic syndrome may present with the following symptoms:
- Peripheral edema (the ankle swelling part…)
- Ascites (the fancy word for free fluid in the abdomen)
- Pleural effusion
- A history of recurrent infections
- Muehrcke’s lines — curved, white lines running across the nail beds
Lab tests can be used to help identify nephrotic syndrome. Urinalysis will reveal massive proteinuria, lipiduria, waxy casts, and oval fatty bodies. The protein is lost due to the damaged basement membrane being unable to retain the proteins. The fat in the urine is a result of the liver trying to replace the protein loss by making lipoproteins. A compreshensive metabolic panel (CMP) will show hypoproteinemia, hypoalbunimemia, and hypercholesterolemia. The CMP findings are correlated to the urinalysis findings.
Renal biopsy is used to confirm the diagnosis of nephrotic syndrome.