Clinical

PHM17 session summary: Kawasaki Disease updates


 

At PHM 2017

NASHVILLE, TENN. – A panel of experts discussed highlights from the 2017 AHA Kawasaki Guidelines at Pediatric Hospital Medicine, sponsored by the Society of Hospital Medicine, the American Academy of Pediatrics, and the Academic Pediatric Association.

Session

Kawasaki Disease Reconsidered: New AHA Guidelines

Presenters

John Darby, MD, Marietta DeGuzman, MD, Kristen Sexson, MD, PhD, MPH, Stanford Shulman, MD, Nisha Tamaskar, MD

Session summary

For the second year in a row, the session highlighting American Heart Association updates on Kawasaki disease did not disappoint and again attracted a large crowd of community and academic pediatric hospitalists. The newly-revised 2017 AHA Kawasaki Guidelines hot off the press by McCrindle et al. was reviewed in detail.

Dr. Erin King, associate program director, University of Minnesota Pediatric Residency Program
Dr. Erin King
Hospitalists agree that Kawasaki disease (KD), both classic and incomplete, is being diagnosed more frequently than even a few years ago. Clues to an underlying etiology have been found by Dr. Anne Rowley and colleagues at Northwestern, who found the potential presence of microscopic viral inclusion bodies seen in the columnar epithelium of the respiratory tract of deceased patients with severe disease. This is thought to be due to a ubiquitous organism with likely genetic susceptibility for certain individuals.

A secondary theory investigates the tropospheric wind patterns from central Asia and has indicated a possible link to outbreaks of KD in Chile. Despite previous investigation of carpet cleaning and risk for KD, no causal link has been identified.

Dr. Akshata Hopkins, assistant professor of pediatrics, Johns Hopkins All Children's Hospital
Dr. Akshata Hopkins
A majority of hospitalists in attendance indicated they treat with 2 g/kg of intravenous immunoglobulin (IVIG) with high-dose adult-strength aspirin (ASA) and retreat for recurrence of fever within 36-48 hours of completion of the initial IVIG infusion. There is not widespread use of immunomodulating agents or steroids as primary treatment. In addition, most hospitalists treat on the 5th day of fever with some exceptions at the 4th day of symptoms. Caution was advised against early treatment as significant overlap is seen with Kawasaki and adenovirus disease as adenovirus recrudescence can be seen with KD.

Experts addressed pathophysiology, diagnosis, and management. Below are highlights from the new 2017 AHA Kawasaki Guideline Update in conjunction with points from the panel discussion.

Pathophysiology

• Cause is likely to be a common ubiquitous agent that in genetically inclined children will lead to a particular inflammatory response that manifests clinically as KD.

• A new theory about how the “ubiquitous agent” is spread by wind patterns.

Diagnosis

• Confirmed that infants younger than 1 year of age are more difficult to diagnose because they don’t present classically so it must be on the differential.

• The new algorithm makes it clearer that infants with fever for 7 days without symptoms should get lab screening tests for KD.

• Those who have classic symptoms and lab abnormalities consistent with KD but in whom fever is still at 3-4 days may be diagnosed with KD prior to the “5 days of fever rule” because these tend to be a sicker cohort of patients with higher rate of complications. Pretest probability and suspicion for KD must be high to treat before 5 days.

• Importance of the Z-score when evaluating an echocardiogram completed on a patient with suspected KD was stressed with a score greater than or equal to 2.5 reaching a level of significance for the patient’s body size.

Management

• It is still agreed that IVIG is first line therapy.

• For refractory KD (not responsive within 36 hours of first dose IVIG), management is more controversial. Experts on the panel agreed that they would likely provide a second dose of IVIG before thinking about steroids.

• Moderate dose aspirin is just as effective as high dose aspirin in the acute phase of KD.

• For more detailed information regarding the role of corticosteroids in KD, refer to Dr. Carl Galloway’s article in The Hospitalist July 2017 issue.

• A certain subset of patients may benefit from steroids if given early in the disease course, including those who present in shock syndrome. Steroids would still be in conjunction with IVIG treatment.

• Even though the new guidelines recommend a longer course of steroids for those refractory cases of KD in high-risk patients, panel experts are still unsure about evidence behind the claim.

The RAISE study was referenced and indicates there are significantly different outcomes for patients with severe disease placed on steroid therapy in combination with IVIG. In this group of patients, the incidence of coronary artery aneurysms was 23% in the IVIG-only group compared to 3% in the IVIG + steroid group (P less than .0001). This study and a recent Cochrane review that supported use of steroids in KD were completed in a homogeneous population of Japanese children and may not be generalizable to children in the United States.

Hyponatremia has been used as a diagnostic criterion for severe KD in Japanese children and was referenced as an indicator for addition of steroid therapy. Also, studies investigating the necessity of ASA at 80-100 mg/kg/d, a common practice for patients with KD treated in the United States, were compared to medium-dose ASA (30-50 mg/kg/d). There was no clinically significant difference in patient outcome or development of aneurysm formation between these two dosing regimens.

Key takeaways for Pediatric HM

• Diagnosis of classic KD remains unchanged and includes 5 or more days of fever and at least four clinical features (extremity changes, rash, conjunctivitis, oral changes, and cervical lymphadenopathy).

• Infants with fever of 7 days or more without other explanation should be evaluated for KD.

• Echocardiographic findings should be adjusted for body surface area and are significant if Z-score greater than or equal to 2.5.

• Moderate- to high-dose ASA is appropriate as an adjunct to IVIG until the patient is afebrile.

• Steroid therapy (for a total of 14 days) should be considered for high-risk patients.

Dr. King is associate program director, University of Minnesota Pediatric Residency Program. Dr. Hopkins is assistant professor of pediatrics, Johns Hopkins All Children’s Hospital.

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