A 32-year-old woman from Chennai presents with fever, myalgia, and headache for 3 days. She has a maculopapular rash on her trunk and limbs. Platelet count is 95,000/μL, and NS1 antigen is positive. Which of the following is NOT a recognized feature of dengue fever?

Explanation

## Dengue Fever: Clinical Features — What Is NOT True ### Correct Answer: Petechial Rash Appears Before Maculopapular Rash in All Patients **Key Point:** The rash in dengue follows a predictable but variable pattern. The **maculopapular rash typically appears on days 3–5** of illness and is the most common dermatological finding. **Petechial rash is NOT a universal feature** and when present, it usually appears *after* the maculopapular rash, not before. The statement "in all patients" makes this option definitively wrong. ### Why the Other Three Options ARE Correct | Feature | Evidence | Timing/Frequency | |---------|----------|------------------| | Relative bradycardia despite fever | Classic finding in dengue; heart rate disproportionately low for fever degree | Present in febrile phase | | Thrombocytopenia (days 3–5) | Platelet nadir typically occurs as fever subsides; count <100,000/μL in ~50% | Critical sign of dengue hemorrhagic fever risk | | Hepatomegaly >50% | Common in dengue; liver tenderness may accompany it | Febrile phase; resolves with recovery | **Clinical Pearl:** The **rash sequence in dengue** is: 1. **Maculopapular rash** (days 3–5) — trunk + limbs, spares palms/soles 2. **Petechiae** (if present) — appear later, on pressure areas, not universal 3. **Flushing/erythema** — may precede rash **High-Yield:** Dengue rash is **NOT pruritic or painful** — this distinguishes it from other viral exanthems. The absence of petechiae in many dengue cases makes the statement "petechiae appear first in all patients" factually incorrect. [cite:Harrison 21e Ch 189]