Critical Cases - Swollen 2 year old!

A 2 yo female presentes with parents with complaints of "whole body swelling" noted over days. You panic slightly as you reach for possible differentia diagnoses to explain this perplexing symptom and are struck by a distant memory of your peds rotation from medical school, or perhaps a flash of a memory staring at your Robbins textbook of pathophysiology.....

Category (Day):