Pediatric Nephrotic Syndrome Clinical Presentation

Updated: Mar 04, 2020
  • Author: Jerome C Lane, MD; Chief Editor: Craig B Langman, MD  more...
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Edema is the presenting symptom in about 95% of children with nephrotic syndrome. Early on, the edema is intermittent and insidious, and its presence may not be appreciated. A common story is for the child to present to a primary care practitioner repeatedly for periorbital edema, which is ascribed to "allergies" until the edema progresses.

Edema usually appears first in areas of low tissue resistance (eg, the periorbital, scrotal, and labial regions). It can progress rapidly or slowly. Ultimately, it becomes generalized and can be massive (anasarca). The edema is pitting and typically dependent, being more noticeable in the face in the morning and predominantly in the lower extremities later in the day.

A history of a respiratory tract infection immediately preceding the onset of nephrotic syndrome is frequent, but the relevance to causation is uncertain. Upper respiratory tract infections, otitis media, and other infections are often associated with relapses of idiopathic nephrotic syndrome (INS) as well. Approximately 30% of children have a history of allergy. A hypersensitivity event, such as a reaction to a bee sting or poison ivy, has been reported to precede the onset of INS in some cases. [1]

Children with nephrotic syndrome occasionally present with gross hematuria. The frequency of macrohematuria depends on the histologic subtype of nephrotic syndrome. It is more commonly associated with membranoproliferative glomerulonephritis (MPGN) than with other subtypes, but its frequency in minimal change nephrotic syndrome (MCNS) has been reported to be as high as 3-4% of cases.

Statistically, a higher percentage of patients with focal segmental glomerulosclerosis (FSGS) have microhematuria than those with MCNS, but this is not helpful in differentiating between types of nephrotic syndrome in the individual patient.

Given the risk of thrombosis in INS, renal vein thrombosis must be considered in patients with significant hematuria. Rarely, a child can present with other symptoms secondary to thrombosis, such as seizure caused by cerebral thrombosis.

A child might be brought to medical attention for symptoms of infection, such as fever, lethargy, irritability, or abdominal pain due to sepsis or peritonitis. Peritonitis can be mistaken for appendicitis or other cause of acute abdomen unless the child's proteinuria and edema are appreciated.

Anorexia, irritability, fatigue, abdominal discomfort, and diarrhea are common. Gastrointestinal distress can be caused by ascites, bowel wall edema, or both. Respiratory distress can occur, due to either massive ascites and thoracic compression or frank pulmonary edema and effusions, or both.

Except in rare cases of familial INS, no significant family history of kidney disease or INS is usually noted. Children are typically healthy prior to the onset of INS and, except for the history of allergy and atopy noted above, do not usually have a significant past medical history related to INS.


Physical Examination

The most common clinical finding is edema. The edema is pitting and is typically found in the lower extremities, face and periorbital regions, scrotum or labia, and abdomen (ascites). In those children with marked ascites, mechanical restriction to breathing may be present, and the child may manifest compensatory tachypnea. Pulmonary edema and effusions can also cause respiratory distress. Hypertension can be present and is more common in children with FSGS and MPGN than in those with MCNS.

Physical findings of the complications of INS can also be evident. Abdominal tenderness might indicate peritonitis. Hypotension and signs of shock can be present in children with sepsis. Thrombosis can cause various findings, including tachypnea and respiratory distress (pulmonary thrombosis/embolism), hematuria (renal vein thrombosis), and seizure (cerebral thrombosis).