Question

A 2-year-old presents with fever, lethargy, and petechial rash on trunk and extremities. What is the most likely diagnosis?

• A. Henoch-Schönlein purpura (HSP)
• B. Meningococcemia
• C. Measles
• D. Kawasaki disease

Hint:

Any acute febrile child presenting with a non-blanching petechial or purpuric rash must be treated empirically for meningococcemia with immediate parenteral third-generation cephalosporins (e.g., Ceftriaxone) without awaiting lab results.

Answer 1

The Correct Option is B

Concept:
Meningococcemia, caused by Neisseria meningitidis, is an acute, life-threatening septicemia characterized by rapid progression of high fever, toxic appearance, septic shock, disseminated intravascular coagulation (DIC), and a characteristic purpuric/petechial rash.
Explanation:
• Neisseria meningitidis releases potent endotoxins (lipooligosaccharides) directly into the circulation, triggering massive proinflammatory cytokine release, diffuse endothelial injury, vascular permeability, and microvascular thrombosis.

• The cutaneous hallmark of meningococcemia begins as discrete erythematous macules or petechiae that rapidly coalesce into extensive purpura fulminans and ecchymoses with central cutaneous necrosis across the trunk and extremities.

• The acute onset of high fever accompanied by lethargy, altered sensorium, poor peripheral perfusion, and a rapidly spreading petechial/purpuric rash in a toddler is classic for fulminant meningococcal septicemia.

• Henoch-Schönlein purpura (IgA vasculitis) features non-thrombocytopenic palpable purpura symmetrically distributed over dependent areas (lower limbs and buttocks) and is usually not accompanied by acute high-grade septic fever or toxic lethargy.

• Measles presents with a craniocaudal progression of a morbilliform, erythematous, non-petechial maculopapular rash preceded by the classic triad of cough, coryza, and conjunctivitis with Koplik spots.

• Kawasaki disease presents with prolonged fever ($\ge$ 5 days), bilateral non-purulent conjunctivitis, polymorphic erythematous rash (non-petechial), strawberry tongue, cervical lymphadenopathy, and extremity changes.
Final Answer:
The combination of acute high-grade fever, lethargy, toxic presentation, and rapidly progressive petechial-purpuric rash on the trunk and extremities represents meningococcemia.