A 28-year-old man from Delhi is on day 7 of dengue fever. He has recovered from the acute phase but now presents with persistent abdominal pain, vomiting, and a platelet count of 40,000/μL. Which of the following is NOT a recognized complication or feature of dengue hemorrhagic fever (DHF)?

Explanation

## Dengue Hemorrhagic Fever (DHF): Complications — What Is NOT a Primary Feature ### Correct Answer: Myocarditis with Acute Left Ventricular Dysfunction as a Primary Manifestation **Key Point:** While **myocarditis can occur in dengue**, it is **NOT a primary or characteristic feature** of DHF. The hallmark of DHF is **plasma leakage** (capillary permeability), leading to hemoconcentration, thrombocytopenia, and hemorrhage — not primary cardiac dysfunction. Myocarditis is a rare complication, not a defining criterion. ### Why the Other Three Options ARE Correct Features of DHF | Feature | Mechanism | Clinical Significance | |---------|-----------|----------------------| | Plasma leakage → hemoconcentration | Increased capillary permeability; fluid shifts to interstitium | Elevated hematocrit (>20% rise) is a diagnostic criterion | | Spontaneous bleeding | Thrombocytopenia + coagulopathy + endothelial damage | Petechiae, ecchymoses, GI bleed, hemoptysis | | Thrombocytopenia <100,000/μL | Bone marrow suppression + consumption | Correlates with hemorrhagic risk | **Mnemonic: DHF Triad** = **Plasma Leakage + Thrombocytopenia + Hemorrhage** - **P**lasma leakage (hemoconcentration) - **T**hrombocytopenia (<100,000) - **H**emorrhage (spontaneous bleeding) ### DHF vs. DSS (Dengue Shock Syndrome) ```mermaid flowchart TD A[Dengue Fever Day 3-5]:::outcome --> B{Plasma leakage?}:::decision B -->|No| C[Uncomplicated Dengue]:::outcome B -->|Yes| D[DHF Criteria Met]:::outcome D --> E{Circulatory collapse?}:::decision E -->|No| F[DHF Grade I-II]:::outcome E -->|Yes| G[DSS Grade III-IV]:::urgent G --> H[Shock, organ failure]:::urgent ``` **Clinical Pearl:** **Myocarditis in dengue** is: - Rare (<1% of cases) - Usually subclinical (mild troponin elevation) - NOT a defining criterion for DHF - Distinct from the **primary pathology** (plasma leakage + thrombocytopenia) **High-Yield:** The **four criteria for DHF diagnosis** are: 1. Fever (current or recent) 2. Hemorrhagic manifestations (positive tourniquet test, petechiae, ecchymoses, or spontaneous bleeding) 3. Thrombocytopenia (<100,000/μL) 4. Evidence of plasma leakage (elevated hematocrit, pleural effusion, ascites, or hypoalbuminemia) **Myocarditis is NOT part of the diagnostic criteria.** [cite:Harrison 21e Ch 189]