A 28-year-old man from Chennai presents on Day 4 of fever with severe headache, retro-orbital pain, myalgia, and a petechial rash on the trunk. NS1 antigen is positive. Platelet count is 45,000/μL, haematocrit is 38%, and AST is 120 U/L. What is the most appropriate next step in management?

Explanation

## Management of Dengue with Warning Signs (DHF Grade I) **Key Point:** This patient has **dengue fever with warning signs** (thrombocytopenia <100,000/μL, rising haematocrit, hepatitis). Management is **supportive care and close monitoring** in hospital; fluid resuscitation is titrated based on evidence of plasma leakage. ### Classification of Dengue Severity | Grade | Platelet Count | Haematocrit Rise | Clinical Features | Management | |-------|---|---|---|---| | **DF (Dengue Fever)** | >100,000 | <20% | Fever, myalgia, rash | Outpatient; ORS, paracetamol | | **DHF I** | <100,000 | <20% | + Bleeding manifestations | Admit; IV access; monitor | | **DHF II** | <100,000 | >20% | Spontaneous bleeding | IV fluids; transfusion ready | | **DHF III/IV (DSS)** | <100,000 | >20% + Shock | Circulatory collapse | ICU; aggressive fluid resuscitation | **High-Yield:** This patient has **DHF Grade I** (platelets 45,000, mild haematocrit rise, hepatitis). The next step is **admission and monitoring**, NOT immediate transfusion. ### Management Algorithm for DHF ```mermaid flowchart TD A[Dengue with warning signs<br/>Platelets <100k, Hct rise, hepatitis]:::outcome A --> B[Admit to hospital]:::action B --> C[Establish IV access<br/>Monitor vitals, urine output]:::action C --> D{Signs of plasma leakage?<br/>Hct rise >20%, hypotension}:::decision D -->|No| E[Maintenance IV fluids<br/>1.5 L/day RL or NS]:::action D -->|Yes| F[Increase IV fluids to 100 mL/kg/day]:::action E --> G{Bleeding or<br/>Hct >45%?}:::decision G -->|Yes| H[Platelet/Fresh frozen plasma transfusion]:::action G -->|No| I[Continue monitoring<br/>Daily CBC, coagulation profile]:::action F --> J{Shock develops?}:::decision J -->|Yes| K[ICU admission<br/>Aggressive fluid resuscitation]:::urgent J -->|No| L[Wean fluids as Hct stabilizes]:::action ``` **Clinical Pearl:** Platelet transfusion is given **only if spontaneous bleeding occurs or platelet count <20,000/μL with bleeding risk**, NOT prophylactically. Premature transfusion increases thrombotic risk. ### Why This Patient Needs Admission - Platelets 45,000/μL (warning sign) - Haematocrit 38% (baseline; watch for rise) - AST 120 U/L (hepatitis; marker of severity) - Day 4 of fever (critical phase beginning; risk of plasma leakage peaks Days 3–5) [cite:Park 26e Ch 14; NVBDCP Dengue Guidelines]