Crack The Case: Periorbital Edema and Abdominal Distention in a Previously Healthy Toddler

Evaluation of a child with edema can be stress-inducing given the differential diagnoses invoked including nephrotic syndrome, liver disease, and heart failure. Determining the cause involves dusting off some principles of physics. Protein, namely albumin, hangs onto water to maintain intravascular osmotic pressure. Not having enough protein causes leakage into surrounding tissues to create characteristic puffiness, begging the question: are we losing protein or not making enough? If protein and osmosis are not the primary drivers, we must also consider capillary hydrostatic pressure as we see with the engorged vessels of heart disease or the retention of fluids with chronic kidney disease. This case investigates a toddler with an initial complaint of periorbital edema and abdominal distention to frame an approach to edema in pediatrics.