What is the primary concern for a child under 5 with fever, rash, and strawberry tongue, but no conjunctivitis or exudate?

Kawasaki Disease: Primary Concern

The primary concern is Kawasaki disease (KD), which requires immediate evaluation with inflammatory markers (ESR, CRP) and echocardiography, as untreated disease leads to coronary artery aneurysms in 15-25% of cases. 1

Why Kawasaki Disease is the Priority

The absence of exudate (no exudative conjunctivitis or pharyngitis) and presence of non-purulent conjunctivitis strongly favor Kawasaki disease over bacterial infections like scarlet fever. 1 The American Heart Association explicitly states that exudative conjunctivitis and exudative pharyngitis are characteristics suggesting diseases other than Kawasaki disease. 1

Classic KD Features Present:

• Fever ≥5 days 1, 2
• Strawberry tongue (oral mucosal changes) 1, 2, 3
• Rash (polymorphous) 1, 2, 3

Missing Features to Assess:

• Bilateral non-purulent conjunctival injection (specifically NON-exudative) 1
• Extremity changes (erythema, edema of hands/feet, or later desquamation) 1, 2
• Cervical lymphadenopathy (≥1.5 cm, often unilateral) 1, 2, 3

Immediate Diagnostic Algorithm

If fever ≥5 days with 2-3 KD features (including strawberry tongue and rash), immediately measure ESR and CRP: 1, 2

If ESR ≥40 mm/hr and/or CRP ≥3 mg/dL:

• Complete blood count (looking for anemia, WBC >15,000/mm³) 1, 2
• Comprehensive metabolic panel (albumin <3.0 g/dL, elevated ALT) 1, 2
• Urinalysis (≥10 WBC/hpf suggests sterile pyuria) 1, 2
• Echocardiography (assess for coronary artery changes, pericardial effusion, decreased LV function) 1, 2
• Platelet count (often >450,000 after day 7) 1, 2

If ≥3 supplemental laboratory findings are positive OR echocardiogram shows abnormalities:

Treat as incomplete Kawasaki disease with IVIG 2 g/kg single dose plus high-dose aspirin (80-100 mg/kg/day divided into 4 doses). 1, 2, 3

Critical Age-Specific Consideration

Children under 5 years, especially infants under 1 year, are at highest risk for incomplete KD and paradoxically have higher rates of coronary artery aneurysms if untreated. 1, 2 Infants <6 months with fever ≥7 days require laboratory testing and echocardiography even with minimal clinical features. 1

Why Not Scarlet Fever?

Scarlet fever typically presents with exudative pharyngitis and a positive rapid strep test, neither of which fit this presentation. 2, 4 The absence of pharyngeal exudate strongly favors Kawasaki disease over scarlet fever. 4 While both conditions cause strawberry tongue and rash, the non-exudative nature of findings in this case points away from Group A Streptococcal infection. 2, 4

Common Diagnostic Pitfalls to Avoid

Do not dismiss KD because conjunctivitis is absent—incomplete KD is more common in young children and carries the same coronary artery risk. 1, 2 The American Heart Association warns that patients with prominent symptoms can be misdiagnosed: fever and rash may be attributed to antibiotic reactions, or cervical lymphadenitis may be mistaken for bacterial adenitis. 1

Do not wait for all 5 classic criteria before initiating workup. 1, 2 Treatment within 10 days of fever onset reduces coronary artery abnormalities from 15-25% to approximately 5%, and giant aneurysms to 1%. 1, 3

Mortality and Morbidity Impact

Untreated Kawasaki disease leads to myocardial infarction, sudden death, or ischemic heart disease in 15-25% of children. 1 KD has surpassed acute rheumatic fever as the leading cause of acquired heart disease in U.S. children. 1 Prompt IVIG therapy reduces this risk to ~5% for any coronary abnormality and ~1% for giant aneurysms. 1, 2