A 5-year-old boy is brought to the office by his mother, who notes that her son's eyes and feet have looked puffy over the last several weeks. She is unaware of exactly when this began but says the patient had a mild upper respiratory tract infection several weeks ago. The boy has no pain but mentions that his shoes seem to fit tightly and bother him, especially when he runs outside during recess at school. The mother also remarks that the boy's urine has been excessively foamy recently. On further questioning, the mother states that she has seasonal allergies and asks whether her child also has allergies. Physical examination is remarkable for periorbital edema and lower extremity edema. Urinalysis shows 4+ proteinuria but is otherwise unremarkable. Which of the following secondary changes is most likely in this patient?

Question

A 5-year-old boy is brought to the office by his mother, who notes that her son's eyes and feet have looked puffy over the last several weeks.  She is unaware of exactly when this began but says the patient had a mild upper respiratory tract infection several weeks ago.  The boy has no pain but mentions that his shoes seem to fit tightly and bother him, especially when he runs outside during recess at school.  The mother also remarks that the boy's urine has been excessively foamy recently.  On further questioning, the mother states that she has seasonal allergies and asks whether her child also has allergies.  Physical examination is remarkable for periorbital edema and lower extremity edema.  Urinalysis shows 4+ proteinuria but is otherwise unremarkable.  Which of the following secondary changes is most likely in this patient?

Quizplus · Accepted Answer

11ec160b_3a35_3769_9249_e9ca04976f7f_MD0001_00 This child most likely has minimal change disease, the most common cause of nephrotic syndrome in children. It typically presents suddenly after an upper respiratory infection. The classic features of nephrotic syndrome are heavy proteinuria (>3.5 g/day in adults and >50 mg/kg/day in children), hypoalbuminemia (<3 g/dL), generalized edema, and hyperlipidemia. Two mechanisms, underfilling and overfilling, contribute to the pathogenesis of edema in nephrotic syndrome. The underfilling mechanism is particularly significant in minimal change disease in children and presents as follows: (Choice A) When the serum albumin level decreases due to its massive loss in the urine, the liver responds by increasing albumin synthesis. However, the amount of renal albumin loss exceeds the liver synthetic capacity. Educational objective: Minimal change disease is the most common childhood nephrotic syndrome. Increased glomerular capillary permeability causes massive protein (eg, albumin) loss in the urine. Hypoalbuminemia reduces plasma oncotic pressure, which causes a fluid shift into the interstitial space, resulting in edema. Low oncotic pressure also triggers increased lipoprotein production in the liver (ie, hyperlipidemia). __________ References: Pathophysiology, evaluation, and management of edema in childhood nephrotic syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/26793696) The pathophysiology of edema formation in the nephrotic syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/22718186)

A 5-Year-Old Boy Is Brought to the Office by His