Dermatology MCQ - Viral Infections - Skin disease in children with Covid-19

A 7-year-old child presents with persistent high fever for 5 days, bilateral non-purulent conjunctivitis, erythematous cracked lips, a strawberry tongue, and a polymorphous rash. The child is irritable and has swollen hands and feet. Laboratory studies show elevated inflammatory markers (CRP, ESR) and neutrophilia. Which of the following is the most likely diagnosis and its association with COVID-19?

A) Kawasaki disease; temporal association with SARS-CoV-2 infection
B) Scarlet fever; caused by Streptococcus pyogenes
C) Toxic shock syndrome; Staphylococcus aureus exotoxin
D) Measles; caused by measles virus
E) Juvenile idiopathic arthritis; autoimmune etiology

Correct Answer: A) Kawasaki disease; temporal association with SARS-CoV-2 infection

Explanation

This presentation is classic for Kawasaki disease (KD), and during the COVID-19 pandemic, a similar condition termed Multisystem Inflammatory Syndrome in Children (MIS-C) has been recognized, often associated with SARS-CoV-2 infection.

Key Clinical Features of Kawasaki Disease and MIS-C:

• Fever: High-grade, lasting ≥5 days.

• Mucocutaneous Findings:

  • Bilateral non-purulent conjunctivitis

  • Erythematous, cracked lips and strawberry tongue

  • Polymorphous rash (often maculopapular)

• Extremity Changes: Swollen hands and feet with subsequent desquamation during convalescence.

• Other Features: Irritability, cervical lymphadenopathy, coronary artery aneurysms (in KD).

• Laboratory Findings: Elevated CRP, ESR, neutrophilia, thrombocytosis (later in course).

Association with COVID-19:

• MIS-C is a post-infectious hyperinflammatory syndrome occurring 2-6 weeks after SARS-CoV-2 infection (often asymptomatic or mild).

• It shares features with KD but often has greater gastrointestinal involvement (abdominal pain, diarrhea) and myocardial dysfunction.

• Pathophysiology: Believed to be due to immune dysregulation post-SARS-CoV-2, resembling a superantigen-driven process.

Why Not the Other Options?

• (B) Scarlet fever: Caused by group A Streptococcus, presents with sandpaper rash, Pastia's lines, and desquamation, but no conjunctivitis or lip changes.

• (C) Toxic shock syndrome: Caused by Staphylococcal or Streptococcal exotoxins, presents with hypotension, diffuse rash, and multi-organ failure.

• (D) Measles: Presents with Koplik spots, cough/coryza/conjunctivitis, and a rash that starts on the face. No swollen hands/feet or strawberry tongue.

• (E) Juvenile idiopathic arthritis: Causes chronic arthritis, fever, and rash but lacks the acute mucocutaneous findings of KD/MIS-C.

Management:

• Intravenous immunoglobulin (IVIG) and high-dose aspirin are first-line for KD and MIS-C.

• Corticosteroids may be used in refractory cases.

• Cardiac monitoring (echocardiogram) to detect coronary artery aneurysms.

Prognosis:
Most children recover with treatment, but delayed diagnosis can lead to coronary complications.

Note: MIS-C is a serious condition requiring prompt recognition and treatment. Always test for SARS-CoV-2 infection (PCR or antibodies) in children presenting with KD-like features during the pandemic.