A 28-year-old man presents with 5 days of high fever, severe headache, retroorbital pain, myalgia and macular rash. WBC 2.4 × 10⁹/L, platelet count 68 × 10⁹/L, haematocrit 46%. NS1 antigen is positive on day 2 of fever. By day 6 the platelet count falls to 18 × 10⁹/L with haematocrit rising to 52% and the patient develops restlessness and abdominal pain. According to WHO 2009 dengue classification, this patient is classified as:
- A Dengue without warning signs
- B Severe dengue (dengue shock syndrome)
- C Dengue haemorrhagic fever Grade I
- D Dengue with warning signs (abdominal pain, rising haematocrit with rapid platelet fall) ✓
Explanation
WHO 2009 dengue classification uses: dengue without warning signs, dengue with warning signs, and severe dengue. Warning signs include abdominal pain or tenderness, persistent vomiting, clinical fluid accumulation, mucosal bleeding, lethargy, liver enlargement >2 cm, and laboratory: increase in haematocrit concurrent with rapid decrease in platelet count. This patient has abdominal pain and the characteristic haematocrit rise (≥20% = 46% rising to 52%) with platelet fall — classic warning signs. Severe dengue requires shock, severe bleeding, or severe organ impairment. The old DHF grading (Grades I–IV) has been replaced by the 2009 classification.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.