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HeikkiTuikkala

Kawasaki Disease

Essentials

  • Acute paediatric febrile disease that may lead to coronary artery aneurysms if untreated
  • Early diagnosis and intravenous immunoglobulin treatment lessen the risk of coronary aneurysms.
  • The disease should be suspected when a small child has a highly febrile disease that does not respond to antimicrobial treatment even if not all the symptoms required for the diagnosis were identified.

Pathology

  • Kawasaki disease is an acute high febrile vasculitis affecting children. If left untreated it leads to coronary artery dilatation in 20% of the patients.
  • The aetiology is unknown, but it is probably a reaction triggered by an infection.

Diagnosis

  • Diagnosis is based on the clinical picture. The patient has a fever of at least 38°C for several days and the following symptoms:
    1. Conjunctival injection; no discharge or exudate
    2. Changes in the mouth (at least one of the following): strawberry tongue, erythema of the pharynx and oral mucosa, and red and cracked lips
    3. Changes in the peripheral extremities (at least one of the following): swelling of the hands and feet, erythema of the palms and soles, peeling of the skin of the hands and feet about two weeks after the onset of the disease
    4. Rash, which can be very diverse, most commonly erythematous or urticarial
    5. Enlargement of a cervical lymph node over 1.5 cm
  • Fever which has lasted for at least 5 days and 4 of the 5 main symptoms are required for the diagnosis.
    • When the clinical picture is clear, an experienced clinician can make the diagnosis already on the 4th fever day.
    • Sometimes the diagnosis has to be made on the basis of 2-3 characteristic symptoms, in which case the term used is incomplete Kawasaki disease.
  • The disease should be suspected and the child referred for further investigations even if not all the listed symptoms were identified.
  • CRP is usually increased to over 30 mg/l.
  • Children below 6 months of age may lack some of the symptoms. Kawasaki disease should be suspected in an infant with unexplained febrile illness.
  • All symptoms are not always present at the same time; take a good history from the parents.
  • About half of the patients have additional symptoms, such as otitis media, diarrhoea or abdominal pain. Twenty-five per cent have aseptic meningitis, joint pain or arthritis.
  • Other illnesses causing similar symptoms should be ruled out (for example scarlet fever, MIS-C Multisystem Inflammatory Syndrome in Children (Mis-C) with Covid-19 Infection).
  • See article 2 (open access) for illustrative pictures of the clinical manifestations of the disease.

Laboratory findings

  • Fit any bacterial illness
    • CRP and sedimentation rate clearly elevated
    • Leucocytosis and left shift in differential white cell count
    • Often sterile pyuria
    • Alanine aminotransferase (ALT) concentration often increased

Complications

  • In about 20% of untreated patients coronary artery enlargement or aneurysms develop. These may be thrombosed and lead to myocardial infarction and sudden death. Some of the milder aneurysms regress spontaneously; others leave stenoses, obstructions or tortuosity.
  • Coronary aneurysms can be detected in cardiac ultrasonography. It should be carried out at once when Kawasaki disease is suspected, and repeated about 2 weeks and again a month after the onset of the disease to detect possible changes.

Treatment Intravenous Immunoglobulin for the Treatment of Kawasaki Disease, Corticosteroids for Kawasaki Disease in Children, Tnf Blockers for Kawasaki Disease in Children, Salicylate for the Treatment of Kawasaki Disease in Children

  • High-dose intravenous immunoglobulin in one dose. The treatment efficiently prevents coronary enlargement and brings prompt alleviation of symptoms.
  • In addition to treatment with immunoglobulins, also glucocorticoids may be used and, in cases refractory to treatment, immunomodulatory therapies.
  • Treatment should be started as soon as possible when Kawasaki disease is suspected, preferably within a week of disease onset. Hence it is important to suspect the disease and send the children to hospital in time for early treatment.
  • The administration of live vaccines (e.g. MMR, chickenpox and rotavirus vaccine) should be postponed until at least 11 months have passed after the immunoglobulin treatment.

Follow-up and prognosis

  • The majority of children recover from the Kawasaki disease fully, and they do not develop coronary artery changes.
  • The patients who have developed coronary artery aneurysms need long-term cardiological follow-up because of e.g. an increased risk of thrombosis.
  • If coronary artery changes do not develop, the specialized care follow-up ends when one year has passed. A 2020 international review recommends that the follow-up of these patients is done in primary care (see 3).
  • Healthy living habits and avoiding the risk factors of arterial disease should be recommended to the patients because there is insufficient knowledge of whether history of Kawasaki disease increases the risk of developing cardiovascular diseases prematurely.

    References

    • McCrindle BW, Rowley AH, Newburger JW ym. Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association. Circulation 2017;135(17):e927-e999. [PubMed]
    • Saguil A, Fargo M, Grogan S. Diagnosis and management of kawasaki disease. Am Fam Physician 2015;91(6):365-71. [PubMed]
    • Brogan P, Burns JC, Cornish J et al. Lifetime cardiovascular management of patients with previous Kawasaki disease. Heart 2020;106(6):411-420. [PubMed]