Food allergy masquerading as persistent proteinuria in post-infectious glomerulonephritis: a case report

Background: Post-infectious glomerulonephritis (PIGN) is one of the most common causes of pediatric acute glomerulonephritis. Immune system dysregulation manifesting as food allergy may predispose PIGN patients to nephrotic-range proteinuria. Case Presentation: The patient was a 3-year-old male that presented with edema, gross hematuria and reduced urine output following a mild fever, rhinorrhea and lethargy. Due to the persistence of proteinuria and hematuria, he underwent a kidney biopsy. The patient was diagnosed with atypical PIGN and was placed on oral prednisolone. During treatment, a relationship between the consumption of dairy products and the degree of proteinuria was noted. The clinical manifestations and urinalysis indices improved upon steroid discontinuation and initiation of a hypoallergic diet. Conclusion: The association between the degree of proteinuria and consumption of dairy products in this PIGN patient led to the identification of food allergy as an underlying factor for nephrotic-range proteinuria.