You don’t need any lab work to diagnose typical Kawasaki disease (KD). It’s all a clinical diagnosis. However, in ambiguous cases, certain lab findings characteristic of KD may support the diagnosis.
Supplemental laboratory testing can help in the diagnosis of these atypical Kawasaki cases.
The AHA/AAP recommended the following labs to evaluate atypical Kawasaki disease.
- CRP or ESR – Acute-phase reactants
- CBC with diff.
- Urinalysis (preferably clean catch)
- CMP (Serum ALT, Serum albumin)
Laboratory findings suggestive of KD include the following:
- CRP ≥3 mg/dL or ESR ≥40 mm/hour)
- WBC count ≥15,000/microL
- Anemia for age (Normocytic, normochromic)
- Platelet cell count ≥450,000/microL after seven days of illness
- Non-neutrophilic (sterile) pyuria (≥10 WBCs/high-power field)
- Serum alanine aminotransferase level >50 units/L
- Serum albumin ≤3 g/dL (Hypoalbuminemia)
Supplemental laboratory criteria (not required for diagnosis) to help with atypical Kawasaki
CRP = C-reactive protein; ESR = erythrocyte sedimentation rate; CBC with diff = Complete blood count (CBC) with differential white blood cell (WBC) count