What is the appropriate management for a 9-year-old patient presenting with unilateral cervical lymph node swelling, mild eczematous changes on fingertips and plantar surfaces, and fever?

Kawasaki Disease Management

This 9-year-old with fever, unilateral cervical lymphadenopathy, and bilateral extremity edema (hands and feet) requires urgent evaluation for Kawasaki disease and immediate treatment with intravenous immunoglobulin (IVIG) if diagnostic criteria are met to prevent coronary artery complications. 1

Diagnostic Assessment

The clinical presentation strongly suggests Kawasaki disease (KD), which requires fever for at least 5 days plus at least 4 of 5 principal clinical features 1:

• Cervical lymphadenopathy (≥1.5 cm diameter, usually unilateral) - PRESENT 1
• Erythema and edema of hands and feet in acute phase - PRESENT (described as "equation" which likely means edema) 1
• Bilateral bulbar conjunctival injection without exudate - assess immediately 1
• Erythema and cracking of lips, strawberry tongue, and/or oral/pharyngeal erythema - assess immediately 1
• Rash (maculopapular, diffuse erythroderma, or erythema multiforme-like) - assess immediately 1

Critical Diagnostic Points

The unilateral cervical lymphadenopathy is the least common principal feature and can be the most prominent initial finding, sometimes mimicking bacterial lymphadenitis and delaying KD diagnosis 1. In KD, multiple lymph nodes are enlarged with retropharyngeal edema or phlegmon common, whereas bacterial lymphadenitis typically presents with a single node with hypoechoic core 1.

The non-painful nature of the swelling is consistent with KD, as the lymphadenopathy in KD is typically non-suppurative 1.

Immediate Management Protocol

If Classic KD Criteria Met (≥4 of 5 features):

1. Administer IVIG 2 g/kg as a single infusion within 10 days of fever onset (ideally within 7 days) 1
2. High-dose aspirin 80-100 mg/kg/day divided into 4 doses until fever resolves for 48 hours 1
3. Echocardiography to assess for coronary artery abnormalities 1
4. Laboratory evaluation: CBC, ESR, CRP, liver enzymes, albumin, urinalysis (expect elevated WBC with neutrophil predominance, elevated acute phase reactants, low sodium/albumin, sterile pyuria) 1

Expected Response:

Fever should resolve within 36 hours after IVIG infusion completion; if not, the patient has IVIG resistance requiring additional therapy 1.

Alternative Diagnosis Consideration

While the presentation is most consistent with KD, the "mild eczematous changes" on fingertips and plantar surfaces warrant brief consideration of:

Atopic dermatitis with secondary lymphadenopathy - However, this is unlikely because 1:

• Lymphadenopathy in eczema is typically bilateral and reactive to extensive skin disease 1
• The non-painful, unilateral cervical lymphadenopathy is atypical for eczema-related adenopathy 1
• Fever is not a feature of uncomplicated atopic dermatitis 1
• The described skin changes are minimal ("mild") and would not explain the systemic presentation 1

Critical Pitfalls to Avoid

1. Do not delay treatment waiting for all 5 principal features - diagnosis can be made with 4 features, especially when hand/foot changes are present 1
2. Do not misdiagnose as bacterial lymphadenitis - the persistence of fever beyond antibiotic treatment and development of other KD features would confirm KD 1
3. Do not dismiss the diagnosis if fever spontaneously resolves after 7 days - this does not exclude KD 1
4. Imaging studies (ultrasound or CT) can help differentiate KD lymphadenopathy from bacterial causes if diagnosis is uncertain 1

Monitoring and Follow-up

• Serial echocardiography at diagnosis, 2 weeks, and 6-8 weeks to monitor for coronary artery aneurysms 1
• Transition to low-dose aspirin (3-5 mg/kg/day) once afebrile for 48 hours, continuing for 6-8 weeks if no coronary abnormalities 1
• Thrombocytosis is common in the second week after fever onset 1