In dengue fever, on which day of illness does thrombocytopenia typically reach its nadir and the patient is at HIGHEST risk for plasma leakage?
- A Day 1–2 of fever
- B Day 7–9 (recovery phase)
- C Day 3–6 of fever (critical phase), typically when fever defervesces ✓
- D Throughout the entire febrile period uniformly
Correct answer: C. Day 3–6 of fever (critical phase), typically when fever defervesces
Explanation
In dengue fever, the critical phase occurs around Day 3–6 of illness, classically coinciding with defervescence. During this phase, there is rapid platelet fall, haematocrit rise (indicating plasma leakage), and risk of dengue haemorrhagic fever and dengue shock syndrome. Paradoxically, the fever abating signals the most dangerous period. Recovery phase (Day 7+) is characterized by platelet count rebound and reabsorption of leaked plasma.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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