What is the diagnosis for dengue fever presenting with black tarry stool (melena)?

Dengue Hemorrhagic Fever with Gastrointestinal Bleeding

When a patient with dengue fever presents with black tarry stool (melena), the diagnosis is dengue hemorrhagic fever (DHF) with upper gastrointestinal bleeding, representing a severe manifestation that requires immediate hospitalization and intensive monitoring. 1, 2

Understanding the Clinical Significance

Melena in dengue indicates upper gastrointestinal hemorrhage and qualifies as a danger sign requiring urgent medical attention. 1 This presentation places the patient in the category of dengue with warning signs or severe dengue, depending on hemodynamic status and other complications. 1, 2

Key Diagnostic Considerations

The presence of melena in dengue typically indicates one of two underlying pathologies:

• Peptic ulcer disease (gastric or duodenal ulcers) - Most common cause, found in approximately 50% of dengue patients with upper GI bleeding. 3 Dengue acts as a precipitating factor for peptic ulcer bleeding due to hemostatic derangements including thrombocytopenia and coagulopathy. 3

• Hemorrhagic gastritis or gastroduodenal erosions - The second most common finding on endoscopy in dengue patients with melena. 3

Critical laboratory findings that accompany this presentation include: 1, 4

• Thrombocytopenia (platelet count typically <100,000/mm³, with bleeding risk significantly increased when <70,000/mm³) 4
• Rising hematocrit with concurrent thrombocytopenia (indicating plasma leakage) 1
• Prolonged prothrombin time (INR >2.0) and partial thromboplastin time (>60 seconds) 4

Immediate Management Priorities

Resuscitation and stabilization take precedence: 5, 2

• Hemodynamic assessment - Check blood pressure, pulse pressure (narrow pulse pressure ≤20 mmHg indicates impending shock), heart rate, and capillary refill time. 1, 2

• Fluid resuscitation - If signs of shock are present (hypotension, narrow pulse pressure, cold extremities), administer 20 mL/kg isotonic crystalloid bolus over 5-10 minutes with immediate reassessment. 2 For severe shock with pulse pressure <10 mmHg, consider colloid solutions. 2

• Blood product support - Transfuse packed red blood cells to maintain hemoglobin >7 g/dL (target 9 g/dL if massive bleeding or cardiovascular comorbidities). 5 Correct coagulopathy with fresh frozen plasma if INR >1.5 and platelet transfusion if platelets <50,000/mm³ with active bleeding. 5

• Nasogastric tube insertion - Protect the airway and decompress the stomach in patients with hematemesis or massive melena. 5

Diagnostic Workup

Upper endoscopy (esophagogastroduodenoscopy) is beneficial and recommended to identify structural gastroduodenal lesions when dengue is complicated by hematemesis or melena. 4 This should be performed once the patient is hemodynamically stable. 3

Important pitfall to avoid: Do not assume all bleeding is purely from dengue-related thrombocytopenia. Approximately 50% of dengue patients with upper GI bleeding have underlying peptic ulcer disease that requires specific treatment. 3

Risk Factors for Bleeding

Specific factors that increase bleeding risk in dengue patients include: 4

• Prior antiplatelet drug use (aspirin, clopidogrel) - significantly increases bleeding risk and should be stopped immediately 4, 6
• Platelet count <70,000/mm³ 4
• INR >2.0 4
• Partial thromboplastin time >60 seconds 4
• NSAID use - must be discontinued to minimize bleeding risk 6

Monitoring Requirements

These patients require hospitalization with intensive monitoring: 1, 2

• Daily complete blood count to track platelet counts and hematocrit levels 2
• Continuous monitoring for other warning signs: persistent vomiting, abdominal pain/tenderness, clinical fluid accumulation, lethargy/restlessness, hepatomegaly 1
• Hemodynamic parameters every 2-4 hours initially 2
• Urine output monitoring (target >0.5 mL/kg/hour in adults) 2

Treatment Approach

Supportive therapy forms the cornerstone of management: 3

• Blood transfusions as needed to maintain adequate hemoglobin 3
• Fluid management to maintain perfusion while avoiding over-resuscitation (which can worsen plasma leakage) 1, 2
• Acetaminophen for fever (never aspirin or NSAIDs) 2, 6
• Proton pump inhibitors for peptic ulcer disease if identified 3

Surgical intervention is rarely required - only one patient in a series of 26 dengue patients with upper GI bleeding required surgery for massive duodenal ulcer bleeding. 3 Most cases resolve with supportive therapy and blood transfusions alone. 3

Prognosis

With appropriate recognition and management, mortality can be reduced to <0.5%. 1 Complete recovery typically occurs within 6 weeks, though the critical period is days 3-7 of illness when warning signs typically appear and progression to severe dengue occurs. 1, 7