Kawasaki Disease (KD) Guidelines

Mark Gorelik,¹ Sharon A. Chung,² Kaveh Ardalan,³ Bryce A. Binstadt,⁴ Kevin Friedman,⁵ Kristen Hayward,⁶ Lisa F. Imundo,¹ Sivia K. Lapidus,⁷ Susan Kim,² Mary Beth Son,⁵ Sangeeta Sule,⁸ Adriana H. Tremoulet,⁹ Heather Van Mater,³ Cagri Yildirim-Toruner,¹⁰ Carol A. Langford,¹¹ Mehrdad Maz,¹² Andy Abril,¹³ Gordon Guyatt,¹⁴ Amy M. Archer,¹⁵ Doyt L. Conn,¹⁶ Kathy A. Full,¹⁷ Peter C. Grayson,¹⁸ Maria F. Ibarra,¹⁹ Peter A. Merkel,²⁰ Rennie L. Rhee,²⁰ Philip Seo,²¹ John H. Stone,²² Robert P. Sundel,⁵ Omar I. Vitobaldi,²³ Ann Warner,²⁴ Kevin Byram,²⁵ Anisha B. Dua,¹⁵ Nedaa Husainat,²⁶ Karen E. James,²⁷ Mohamad Kalot,²⁸ Yih Chang Lin,²⁹ Jason M. Springer,²⁵ Marat Turgunbaev,³⁰ Alexandra Villa-Forte,¹¹ Amy S. Turner,³⁰ and Reem A. Mustafa¹²

Guidelines and recommendations developed and/or endorsed by the American College of Rheumatology (ACR) are intended to provide guidance for particular patterns of practice and not to dictate the care of a particular patient. The ACR considers adherence to the recommendations within this guideline to be voluntary, with the ultimate determination regarding their application to be made by the physician in light of each patient’s individual circumstances. Guidelines and recommendations are intended to promote beneficial or desirable outcomes but cannot guarantee any specific outcome. Guidelines and recommendations developed and endorsed by the ACR are subject to periodic revision as warranted by the evolution of medical knowledge, technology, and practice. ACR recommendations are not intended to dictate payment or insurance decisions, and drug formularies or other third-party analyses that cite ACR guidelines should state this. These recommendations cannot adequately convey all uncertainties and nuances of patient care.

The American College of Rheumatology is an independent, professional, medical and scientific society that does not guarantee, warrant, or endorse any commercial product or service.

Objective. To provide evidence-based recommendations and expert guidance for the management of Kawasaki disease (KD), focusing on clinical scenarios more commonly addressed by rheumatologists.

Methods. Sixteen clinical questions regarding diagnostic testing, treatment, and management of KD were developed in the Patient/Population, Intervention, Comparison, and Outcomes (PICO) question format. Systematic literature reviews were conducted for each PICO question. We used the Grading of Recommendations, Assessment, Development and Evaluation method to assess the quality of evidence and formulate recommendations. Each recommendation required consensus from at least 70% of the Voting Panel.

Results. We present 1 good practice statement, 11 recommendations, and 1 ungraded position statement to guide the management of KD and clinical scenarios of suspected KD. These recommendations for KD are focused on situations in which input from rheumatologists may be requested by other managing specialists, such as in cases of treatment-refractory, severe, or complicated KD. The good practice statement affirms that all patients with KD should receive initial treatment with intravenous immunoglobulin (IVIG). In addition, we developed 7 strong and 4 conditional recommendations for the management of KD or suspected KD. Strong recommendations include prompt treatment of incomplete KD, treatment with aspirin, and obtaining an echocardiogram in the setting of unexplained macrophage activation syndrome or shock. Conditional recommendations include use of IVIG with other adjuvant agents for patients with KD and high-risk features of IVIG resistance and/or coronary artery aneurysms. These recommendations endorse minimizing risk to the patient by using established therapy promptly at disease onset and identifying situations in which adjunctive therapy may be warranted.

Conclusion. These recommendations provide guidance regarding diagnostic strategies, use of pharmacologic agents, and use of echocardiography in patients with suspected or confirmed KD.

Kawasaki disease (KD) is a medium vessel vasculitis as presented in the Chapel Hill Consensus Conference nomenclature system (1). It is 1 of 2 primary common vasculitis syndromes that predominantly affect children (the other being IgA vasculitis [Henoch-Schönlein]). KD is seen with relative frequency in young children, at an incidence rate of 25–50 cases per 100,000 persons per year in the US, similar to that of type 1 diabetes (2,3). It typically presents in children <5 years of age as an acute, self-limited febrile disease and is characterized by a combination of several characteristic clinical signs, which include polymorphic rash, nonpurulent conjunctival injection, oropharyngeal and lip mucositis, tongue papillitis, erythema and edema of the hands and feet, as well as unilateral cervical lymphadenopathy.

From a histopathologic perspective, KD is characterized by aggressive neutrophil-mediated panmural vascular necrosis without granuloma formation, followed by intimal hyperplasia and subacute lymphocytic inflammation in advanced disease. It primarily affects the coronary arteries but can also affect medium-caliber arteries throughout the body (4). Therefore, it shares some features with polyarteritis nodosa, and prior to the recognition of KD as a distinct entity, infants with fatal fulminant forms of KD were considered to have “infantile polyarteritis nodosa” (5).

When treated appropriately, KD is associated with a low mortality rate (~0.08% case fatality rate in the largest reported series) (6). However, in the developed world, it is the most common cause of acquired cardiac disease in childhood, with 25% of untreated patients and 5% of treated patients developing coronary artery aneurysms. Among infants <6 months of age, the risk of a coronary artery aneurysm is 50%, even in KD patients who received treatment with intravenous immunoglobulin (IVIG) within the first 10 days of illness (7).

Given increasing options available to treat systemic vasculitis, the American College of Rheumatology (ACR) and Vasculitis Foundation supported the development of guidelines for the management of large, medium, and small vessel vasculitis. This guideline presents evidence-based recommendations for the diagnostic testing, treatment, and management of KD. Recognizing the comprehensive guidelines developed by the American Heart Association (AHA) for the management of KD (3), the guideline focuses on clinical management questions that are generally posed to rheumatologists, such as the use of adjunctive therapies for initial treatment of severe disease and treatment approaches for refractory disease. Although this guideline may inform an international audience, these recommendations were developed considering experience with and availability of treatment and diagnostic options in the US.

This guideline followed the ACR guideline development process (https://www.rheumatology.org/Practice-Quality/ClinicalSupport/Clinical-Practice-Guidelines) using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology to rate the quality of evidence and develop recommendations (8,9). ACR policy guided the management of conflicts of interest and disclosures (https://www. rheumatology.org/Practice-Quality/Clinical-Support/ClinicalPractice-Guidelines/Vasculitis). Supplementary Appendix 1 (available on the Arthritis & Rheumatology website at http:// onlinelibrary.wiley.com/doi/10.1002/art.42041/abstract) presents a detailed description of the methods.

Sixteen clinical questions addressing the diagnostic testing, treatment, and management of KD were developed by the Core Team, initial Voting Panel, and Expert Panel in the Patient/Population, Intervention, Comparison, and Outcomes (PICO) format. The Literature Review Team undertook systematic literature reviews for prespecified PICO questions. The Expert Panel, including rheumatologists and a pediatric cardiologist, provided expert knowledge to inform discussion of the PICO questions and findings of the literature review. This study did not involve human subjects, and therefore, approval from Human Studies Committees was not required.

The initial Voting Panel comprised 9 adult rheumatologists (SAC, AMA, DLC, PCG, PAM, RLR, PS, JHS, AW), 5 pediatric rheumatologists (LFI, SK, SS, MFI, RPS), and 2 patients (KAF, OIV). They reviewed the Literature Review Team’s evidence summaries and formulated and voted on an initial set of recommendations. To incorporate broader expertise from the pediatric community and validate the results from the initial Voting Panel, a second Voting Panel was established and comprised 8 pediatric rheumatologists new to the Voting Panel (MG, KA, BAB, KH, SKL, MBS, HVM, CY-T), 4 pediatric rheumatologists who participated in both Voting Panels (LFI, SK, SS, RPS), a pediatric infectious disease physician with extensive expertise in KD (AHT), and a pediatric cardiologist with extensive expertise in KD (KF). The second Voting Panel also reviewed the Literature Review Team’s findings and independently formulated and voted on recommendations. Members of the second Voting Panel who were not on the initial Voting Panel were not provided with the recommendations formulated by the initial Voting Panel prior to the second panel’s voting. Each recommendation required consensus from at least 70% of the Voting Panel.

How to interpret the recommendations

A strong recommendation is typically supported by moderate- to high-quality evidence (e.g., multiple randomized controlled trials). For a strong recommendation, the recommended course of action would apply to all or almost all patients. Only a small proportion of clinicians/patients would not want to follow the recommendation. For example, an intervention may be strongly recommended if it is considered low-cost, without harms, and the consequence of not performing the intervention may be catastrophic. An intervention may be strongly recommended against if there is high certainty that the intervention will lead to more harm than the comparison with very low or low certainty about its benefit (10).

A conditional recommendation is generally supported by lower-quality evidence or a close balance between desirable and undesirable outcomes. For a conditional recommendation, the recommended course of action would apply to the majority of patients, but the alternative is a reasonable consideration. Conditional recommendations always warrant a shared decisionmaking approach. We specify conditions under which the alternative may be considered.

In one instance, the committee found that the evidence for a particular PICO question did not support a graded recommendation, and the Voting Panel did not favor one intervention over another. However, the Voting Panel believed the PICO question addressed a commonly encountered clinical question, and thus felt that providing guidance for this question was warranted. For this situation, we present an “ungraded position statement” which reflects general views of the Voting Panel.

In this evidence-based guideline, we explicitly used the best evidence available and present it in a transparent manner for the clinician reader/user (10). In some instances, this includes randomized trials in which the interventions under consideration are directly compared. The GRADE system rates evidence that comes exclusively from the collective experience of the Voting Panel and Patient Panel members as “very low–quality” evidence.

For each recommendation, details regarding the PICO questions and the GRADE evidence tables can be found in Supplementary Appendix 2 (http://onlinelibrary.wiley.com/doi/10.1002/ art.42041/abstract).

This is the first guideline issued by the ACR in conjunction with the Vasculitis Foundation for the management of KD. These recommendations constitute a guide to help physicians treat KD. This guideline should not be used by any agency to restrict access to therapy or require that certain therapies must be utilized prior to other therapies.

Patients with KD in the US are often diagnosed and treated by physicians with expertise in areas other than rheumatology (e.g., pediatric cardiologists, hospitalists, or infectious disease specialists). The recommendations in this guideline focus on situations in which rheumatologists are often consulted, such as in the management of severe disease, treatment-refractory disease, arthritis, and MAS with KD. However, these recommendations are relevant to physicians treating KD regardless of their area of expertise.

The AHA has presented recommendations for the initial treatment and long-term management of KD (3). Recommendations presented in this guideline are intended to supplement the AHA guidelines and serve as an additional reference for rheumatologists who may be less familiar with KD. Emerging evidence suggesting that adjunctive therapy decreases the incidence of severe coronary artery aneurysms and accelerates regression of these aneurysms provides the basis for the recommendations concerning “high-risk” KD (23). Although aneurysms that have regressed are affected by endothelial dysfunction and therefore remain abnormal vasculature, normalized vessel caliber decreases the risk of morbidity from vessel thrombosis (3).

Finally, during the COVID-19 pandemic, a novel multisystem inflammatory syndrome in children (MIS-C) associated with SARS–CoV-2 infection emerged, with some features suggestive of KD (60,61). While as many as 50% of these patients could meet criteria for KD, many patients exhibit manifestations that are unusual for KD, including colitis, myocarditis, and neurologic changes, and often present with or develop shock (62). Further study is needed to understand the relationship between MIS-C and KD, especially Kawasaki shock syndrome. Based on clinical experience, recognition and differentiation of these patients from patients with classic KD is important. Patients who fulfill criteria for KD should be treated using the therapies discussed in this guideline. Additional research is needed to determine optimal treatment for MIS-C with and without KD features.

In summary, the ACR and Vasculitis Foundation present these recommendations to assist physicians in managing KD. This guideline can serve as a resource for basic principles of management and will evolve as new treatment strategies for this disease are identified.

We thank Anne M. Ferris, MBBS, Ora Gewurz-Singer, MD, Rula Hajj-Ali, MD, Eric Matteson, MD, MPH, Robert F. Spiera, MD, Linda Wagner-Weiner, MD, MS, and Kenneth J. Warrington, MD, for serving on the Expert Panel. We thank Antoine G. Sreih, MD and Gary S. Hoffman, MD, MS, for their contributions during the early phases of this project as members of the Core Team. Dr. Hoffman’s participation ended July 2018 due to personal reasons. Dr. Sreih’s involvement ended in December 2018 when he became primarily employed by industry, which precluded his continued participation in this project. We thank Joyce Kullman (Vasculitis Foundation) for her assistance with recruitment for the Patient Panel. We thank the patients who (along with authors Kathy A. Full and Omar I. Vitobaldi) participated in the Patient Panel meeting: Jane Ascroft, Scott A. Brunton, Dedra DeMarco, Thomas Fitzpatrick, Jenn Gordon, Maria S. Mckay, Sandra Nye, Stephanie Sakson, and Ben Wilson. We thank Robin Arnold, Catherine E. Najem, MD, MSCE, and Amit Aakash Shah, MD, MPH, for their assistance with the literature review. We thank the ACR staff, including Ms. Regina Parker, for assistance in organizing the face-to-face meeting and coordinating the administrative aspects of the project, and Ms. Cindy Force for assistance in manuscript preparation. We thank Ms. Janet Waters for help in developing the literature search strategy and performing the initial literature search, and Ms. Janet Joyce for performing the update searches.

All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published. Dr. Chung had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study conception and design. Gorelik, Chung, Friedman, Sule, Yildirim-Toruner, Langford, Maz, Abril, Guyatt, Full, Stone, Sundel, Vitobaldi, Husainat, Turgunbaev, Turner, Mustafa.

Acquisition of data. Gorelik, Chung, Binstadt, Lapidus, Kim, Sule, Yildirim-Toruner, Full, Grayson, Stone, Sundel, Byram, Dua, Husainat, James, Kalot, Lin, Springer, Turgunbaev, Villa-Forte, Mustafa.

Analysis and interpretation of data. Gorelik, Chung, Ardalan, Binstadt, Hayward, Imundo, Lapidus, Kim, Son, Sule, Tremoulet, Van Mater, Yildirim-Toruner, Abril, Archer, Conn, Full, Grayson, Ibarra, Merkel, Rhee, Seo, Stone, Sundel, Warner, Byram, Dua, Husainat, Kalot, Lin, Springer, Turgunbaev, Villa-Forte, Mustafa.

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