What causes strawberry tongue in pediatric patients?

What Causes Strawberry Tongue in Pediatric Patients

Strawberry tongue in children is most commonly caused by scarlet fever (Group A Streptococcal infection) or Kawasaki disease, both requiring urgent recognition to prevent serious complications. 1, 2

Primary Causes in Pediatric Patients

Scarlet Fever (Group A Streptococcal Infection)

• Presents with a white-coated tongue that becomes bright red with prominent fungiform papillae, accompanied by fever, sore throat, and a characteristic sandpaper-like rash 1
• Most common in children aged 5-15 years 1, 3
• The strawberry tongue appearance is clinically indistinguishable from Kawasaki disease, making differentiation critical 1

Kawasaki Disease

• Strawberry tongue appears with erythema and prominent fungiform papillae, identical in appearance to scarlet fever 1
• Primarily affects children under 5 years of age, especially in their third year 4, 5
• Untreated Kawasaki disease leads to coronary artery aneurysms in up to 20% of cases, making prompt diagnosis within the first 10 days essential 2, 4
• Oral findings include diffuse erythema of oropharyngeal mucosae, dryness, fissuring, peeling, cracking, and bleeding of the lips 1

Toxic Shock Syndrome

• TSST-1-mediated exanthematous disease can present with strawberry tongue 6
• Shows chronological changes in tongue appearance over the disease course 6

Critical Diagnostic Distinctions

Key Differentiating Features

• The absence of pharyngeal exudate favors Kawasaki disease over scarlet fever 1
• Oral ulcerations and pharyngeal exudates are not typically seen in Kawasaki disease 1
• Scarlet fever presents with sore throat as a prominent feature, while Kawasaki disease does not 1, 3

Diagnostic Algorithm for Fever + Strawberry Tongue + Rash

• If fever ≥5 days with strawberry tongue and rash, immediately check for other Kawasaki disease features: bilateral non-purulent conjunctival injection, extremity changes (erythema/edema of hands/feet), and cervical lymphadenopathy ≥1.5 cm 2
• If only 2-3 Kawasaki disease features present, measure ESR and CRP immediately 2
• If ESR ≥40 mm/hr and/or CRP ≥3 mg/dL, obtain: complete blood count, comprehensive metabolic panel (albumin, transaminases), urinalysis, and echocardiography 2
• Perform rapid strep testing and blood cultures to differentiate bacterial causes from vasculitic conditions 1

Common Diagnostic Pitfalls

Age-Related Considerations

• Incomplete Kawasaki disease is particularly common in infants under 1 year and can present with fewer than 4 principal features, yet carries the same risk of coronary complications 2
• Young infants (<6 months) with prolonged fever (≥7 days) and systemic inflammation require echocardiography even with minimal clinical features due to high risk of coronary complications 2

Misattribution Errors

• Do not attribute strawberry tongue and rash solely to antibiotic reaction if the patient was initially treated for presumed bacterial infection—this is a classic missed diagnosis scenario for Kawasaki disease 2
• Do not dismiss Kawasaki disease because conjunctivitis is absent—incomplete Kawasaki disease is more common in infants and can present with fewer features 2

MIS-C Overlap

• Multisystem Inflammatory Syndrome in Children (MIS-C) presents with overlapping features but typically has more prominent GI symptoms, lower platelet counts, and higher CRP levels than classic Kawasaki disease 2
• SARS-CoV-2 PCR and serology should be obtained to rule out MIS-C 2

Less Common Causes in Pediatric Patients

• Candidiasis can cause a bright red tongue after white plaques are removed, more common in immunocompromised patients 1, 3
• Other viral exanthems (human herpesvirus 6/roseola, parvovirus B19, Epstein-Barr virus, enteroviruses) can cause similar oral findings 2