Clinical Scenario
A 6-year-old boy is admitted with a 5-day history of high-grade fever with chills and vomiting. On the third day of illness, he develops progressive pallor, jaundice, and passes cola-colored urine. On examination, he is pale, icteric, tachycardic, and has mild hepatosplenomegaly. Laboratory investigations reveal:
- Hemoglobin: 5.6 g/dL
- Total bilirubin: 5.8 mg/dL (predominantly indirect)
- Serum creatinine: 2.3 mg/dL
- Platelet count: 65 × 10⁹/L
What is the most likely diagnosis?
A. Autoimmune hemolytic anemia
B. Blackwater fever
C. Hemolytic uremic syndrome
D. Paroxysmal nocturnal hemoglobinuria
E. Wilson disease
Correct answer & Explanation:
Correct Answer: B. Blackwater fever
Explanation: Black water fever/Malaria
This child has massive intravascular hemolysis manifested by:
- Severe anemia
- Jaundice
- Cola-colored urine (hemoglobinuria)
- Acute kidney injury
- Thrombocytopenia
- Fever with chills
These findings are characteristic of blackwater fever, a severe complication of Plasmodium falciparum infection. The dark urine results from hemoglobinuria, not hematuria, due to extensive intravascular destruction of red blood cells. Acute kidney injury develops from hemoglobin-induced tubular injury and hypovolemia.
Why the other options are incorrect
A. Autoimmune hemolytic anemia
Can cause anemia and jaundice but does not typically present with fever with chills, thrombocytopenia, and acute kidney injury.
C. Hemolytic uremic syndrome
Usually follows bloody diarrhea and is characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. Hemoglobinuria with intermittent febrile illness is not typical.
D. Paroxysmal nocturnal hemoglobinuria
Causes recurrent hemoglobinuria and thrombosis but is rare in children and does not present as an acute febrile illness with chills.
E. Wilson disease
May produce hemolytic anemia and jaundice but does not cause the acute febrile presentation or blackwater fever.
Learning Point
Blackwater fever is a manifestation of severe falciparum malaria characterized by:
- Massive intravascular hemolysis
- Hemoglobinuria (“blackwater”)
- Severe anemia
- Jaundice
- Acute kidney injury
It is a medical emergency requiring prompt treatment with intravenous artesunate, supportive care, and blood transfusion when indicated.
