Differential Diagnosis
The patient's symptoms suggest a complex condition with gastrointestinal and renal involvement. The following differential diagnoses are considered:
Single most likely diagnosis
- Hemolytic Uremic Syndrome (HUS): This condition is characterized by the triad of hemolytic anemia, acute kidney injury, and thrombocytopenia. The patient's history of abdominal pain, vomiting, diarrhea, and bloody stools, followed by fatigue, scleral icterus, and decreased urine output, is consistent with HUS. The recent gastrointestinal symptoms in multiple family members suggest a possible infectious etiology, such as E. coli O157:H7.
Other Likely diagnoses
- Acute Kidney Injury (AKI) due to other causes: The patient's decreased urine output and pedal edema suggest AKI, which could be caused by various factors, including dehydration, sepsis, or nephrotoxic substances.
- Thrombotic Thrombocytopenic Purpura (TTP): Although less common in children, TTP is a possibility, characterized by thrombocytopenia, microangiopathic hemolytic anemia, renal failure, and neurological symptoms.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Sepsis: The patient's initial gastrointestinal symptoms and subsequent deterioration could be indicative of sepsis, which requires prompt recognition and treatment.
- Meningococcemia: Although the patient's symptoms do not strongly suggest meningococcemia, it is a life-threatening condition that can present with nonspecific symptoms, including abdominal pain and fatigue.
Rare diagnoses
- Atypical HUS: This condition is characterized by HUS without a clear infectious etiology, often associated with genetic mutations or autoimmune disorders.
- Post-streptococcal glomerulonephritis: Although the patient's symptoms do not strongly suggest this condition, it is a possible cause of AKI and should be considered in the differential diagnosis.