Needing a Diagnostic Kick-start

aka Pediatric Perplexity 008

Reviewed and revised 25 March 2012

A 4 year-old boy has been brought to the emergency department by his worried parents. He has had fevers for the past 6 days. They are concerned because he is not getting better despite repeated visits to a number of doctors. Each time they were told he had a viral illness.

On examination you note the presence of bilateral conjunctivitis, and erythematous rash on his torso and limbs, a 4 cm tender left-sided cervical lymph node and a diffusely red pharynx.

Neck nodule

Neck nodule

Abdominal Rash

Abdominal Rash

Questions

Q1. What is the likely diagnosis?

Kawasaki disease

Also known as Mucocutaneous Lymph Node Syndrome, this vasculitic disorder was first described by Dr. Tomisaku Kawaski in 1967. It is of uncertain etiology, but may be a post-infectious condition.

Q2. How is this diagnosis made?

The diagnosis is made on the basis of the following clinical criteria (A + B):

A. Fever ≥5 days
B. At least 4 of the 5 following physical examination findings:
1. Bilateral, nonexudative bulbar conjunctival injection
bilateral scleral injection with perilimbic sparing
2. Oropharyngeal mucous membrane changes
pharyngeal erythema, red/cracked lips, and a strawberry tongue
3. Cervical lymphadenopathy
with at least one node >1.5 cm in diameter
4. Peripheral extremity changes
acute phase: diffuse erythema and swelling of the hands and feet
convalescent phase: periungual desquamation (weeks 2 to 3)
The diffuse palmar erythema seen in KD is in contrast to the discrete macular lesions of various viral illnesses (e.g., measles) that can sometimes be seen on the palms and soles.
5. A polymorphous generalized rash
Nonvesicular and nonbullous
There is no specific rash that is pathognomonic for KD

The manifestations may appear sequentially rather than concurrently. Atypical cases may not meet all the criteria but may still have the same risks of cardiac complications. These ‘incomplete’ cases occur more often in infants less than 6 months-old — further investigations (see Q5) should be performed if fever of 5 days and 2 or 3 of the other criteria are present.

Clinicians should have a high index of suspicion for this diagnosis in any child with a prolonged fever as early diagnosis and treatment may help prevent the potentially fatal complications of Kawasaki disease.

The approach to ‘incomplete’ Kawasaki disease is summarised nicely in this Paucis Verbis card from Academic Life in Emergency Medicine: Kawasaki disease.

Physical findings consistent with Kawasaki disease are shown below:

(A) Bilateral, non-exudative conjunctival injection with perilimbal sparing. (B) Strawberry tongue and bright red, swollen lips with vertical cracking and bleeding. (C) Erythematous rash involving perineum. (D) Erythema of the palms, which is often accompanied by painful, brawny edema of the dorsa of the hands. (E) Erythema of the soles, and swelling dorsa of the feet. (F) Desquamation of the fingers. (G) Erythema and induration at the site of a previous vaccination with Bacille Calmette-Gurin (BCG). (H) Perianal erythematous desquamation. (From Kim DS, 2006 – click image for source)

Q3. Who gets this condition?

Kawasaki disease may occur in any child of any age, and even adults in some cases. However, it is more common in:

  • children aged < 5 years
  • Asians
  • males (RR 1.5)

Q4. What are the important differential diagnoses?

Diagnosis may be difficult as Kawasaki disease may mimic a number of other conditions:

  • Viral exanthemas including measles
  • Streptococcal disease (e.g. scarlet fever, toxic shock syndrome)
  • Staphylococcal disease (e.g. scalded skin syndrome, toxic shock syndrome)
  • Bilateral cervical lymphadenitis
  • Leptospirosis and rickettsial diseases
  • Stevens-Johnson syndrome and Toxic Epidermal Necrolysis
  • Drug reactions including mercury hypersensitivty reaction
  • Juvenile Chronic Arthritis

Q5. What investigations should be performed?

  • Echocardiography —
    this is the most important investigation to assess for cardiac complications.
    If no abnormalities on presentation the study should be repeated in 4-6 weeks.
  • Laboratory tests —
    Rule out other causes:
    — ASOT, AntiDNAse B, throat swabs, blood cultures
    Non-specific findings seen in Kawasaki disease include:
    — FBC: normochromic anemia and leukocytosis; thrombocytosis (in the 2nd week)
    — LFT changes and hypoalbuminemia
    — increased CRP and ESR
    — Sterile pyuria of ≥10 WBCs per high-power field

The approach to ‘incomplete’ Kawasaki disease is summarised nicely in this Paucis Verbis card from Academic Life in Emergency Medicine: Kawasaki disease.

Q6. What complications may occur?

Cardiac complications:

  • Carditis during the febrile phase
    — myocarditis with ST-T changes (25%), pericardial effusions (20-40%), valvular dysfunction (1-2%) and cardiac failure (~5%)
  • Coronary vessel abnormalities (occur in 20% of cases if untreated and <5% if treated; peaks at 2-4 weeks)
    — aneurysm formation may lead to fatalities from thrombosis, rupture or ischemia-related dysrhythmia (usually within 6 weeks of onset, but may occur many years later.

Kawasaki disease is a vasculitis that can potentially affect almost any organ, it is commonly associated with:

  • arthritis
  • keratitis and uveitis
  • diarrhoea, vomiting and gallbladder disease
  • coryza and cough

Q7. What specific treatment is required?

IV immunoglobulin and aspirin

IV immunoglobulin

  • 2g/kg IV over 10 hours
  • ideally start within 10 days of the onset of the illness
  • a second dose may be given if fevers persist

Aspirin

  • 3-5 mg/kg PO daily for 6-8 weeks
    (when laboratory parameters have fully normalised)
  • some advise higher doses of aspirin until the patient is afebrile or 48-72 hours, but others argue this offers no benefit in addition to treatment with IV immunoglobulin.

Despite these therapies 2-4% of cases still go on to develop coronary artery abnormalities. Corticosteroids may be considered in refractory cases, although there is little evidence supporting their use.

References and links

  • Academic Life in Emergency Medicine — Paucis Verbis: Kawasaki Disease
  • Freeman AF, Shulman ST. Kawasaki disease: summary of the American Heart Association guidelines. Am Fam Physician. 2006 Oct 1;74(7):1141-8. PMID: 17039750.
  • Kim DS. Kawasaki disease. Yonsei Med J. 2006 Dec 31;47(6):759-72. PMID: 17191303; PMCID: PMC2687814.
  • Marx JA, Hockberger R, Walls RM. Rosen’s Emergency Medicine: Concepts and Clinical Practice (7th edition), Mosby 2009. [mdconsult.com]
  • Royal Children’s Hospital Melbourne. RCH Clinical Practice GuidelinesKawasaki disease
  • Wolff AE, Hansen KE, Zakowski L. Acute Kawasaki disease: not just for kids. J Gen Intern Med. 2007 May;22(5):681-4. PMID: 17443379; PMCID: PMC1852903.
Print Friendly

Comments

  1. says

    Gday Chris
    Adenovirus is the virus that looks most like KAwasakis I reckon
    A PNA or NPA is a good early test to check for the viruses that can look like KD
    C

Comments