A 26-year-old man presents with 5 days of high fever, severe headache, retro-orbital pain, myalgia, and a macular rash on day 4. Platelet count is 68,000/µL, AST 180 U/L, haematocrit rising. NS1 antigen is positive. His dengue rapid test shows NS1+, IgM−, IgG−. According to WHO 2009 dengue classification, he is classified as:
- A Severe dengue
- B Dengue without warning signs
- C Dengue haemorrhagic fever grade III
- D Dengue with warning signs ✓
Explanation
WHO 2009 dengue classification replaces the older DHF grading. The three categories are: Dengue without warning signs, Dengue with warning signs, and Severe dengue. Warning signs include: abdominal pain/tenderness, persistent vomiting, clinical fluid accumulation, mucosal bleed, lethargy, liver enlargement >2 cm, rising haematocrit with rapid platelet fall. This patient has a rising haematocrit, platelet count 68,000 (rapidly falling), elevated AST (liver involvement) — these are warning signs. Severe dengue requires severe plasma leakage with shock, severe bleeding, or severe organ impairment. He does not currently meet severe dengue criteria.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.