Addition of the word ‘additional’ oral steroids to the experimental group, Clarification that ‘clinical’ adverse events of any grade related to IVIG, aspirin or corticosteroids should be collected, Removal the following sentence related to IVIG and aspirin ‘They are supplied to the trial participants according the protocol but are NOT under investigation.’, Update to the Funders grant agreement number, Clarification that Echocardiograms and ECGs completed on a scheduled visit should be collected although they are not mandatory for the trial, Clarification that IVIG can be infused dependent as per standard of care within the member state, Typographical error for reason that randomisation will be stratified, should be country rather than site.

Addition of the ISRCTN number, Amendment to the trial compliance statement to allow local national law requirements to be met in EU countries and clarification that in terms of confidentiality GDPR will be followed, Updates to Trial Administration – addition of CTU Data Manager and amendment to the address for the Nursing co-investigator, Amendment of the duration of aspirin given to participants to at least 21 days, Clarification of the 48 hour assessment should be performed within the day 2 assessment, Clarification that the maximum daily temperature will be collected from Day 5 until discharge or until the child/adolescent is afebrile for 2 calendar days, Clarification on the documents required at site assessment, Clarification of the inclusion criteria that the child/adolescent must be below the age of country specific consent for the duration of the trial, Minor typographical amendments to make the wording consistent within the inclusion criteria, Removal of randomisations being completed by the CTU over the phone, Information on the timing of the first dose of corticosteroids, Amendment to the trial IMP dispensing and accountability requirements, Clarification of the data collected for treatment of KD, Addition that adherence to aspirin will be collected using standardised diaries in the control and experimental group, Clarification that echocardiograms collected from any unscheduled timepoints will be centrally assessed, Clarification that only overdose of IMP which results in clinical symptoms of any grade is a notifiable event, Addition of detail regarding the use of IVIG and aspirin during pregnancy, Amendment to the TMG membership.

Addition of details where queries should be sent relating to the sponsorship of the trial, Update to the details within Trial Administration include the addition of the emergency contact details for Paul Brogan and Despina Eleftheriou, addition of a trial manager to the CTU Staff and Affiliates, update to the address and contact details for Cardiology co-investigator Professor Robert Tulloh, Addition that visits maybe conducted via telephone, Clarification that the dose of aspirin should not be reduced until the participant has been afebrile for at least 48 hours, EudraCT# added, Update to the wording ancillary studies to substudies, Addition of urine or blood pregnancy test for adolescents who are menstruating, and exclusion criteria as pregnant or breastfeeding, Removal of LDL and HbA1c collection, Update to the volume of research blood samples collected, Update to the time points weight is collected at, Update to remove collection of temperature from the axilla throughout the protocol, Clarification that if the CHU9D is not available in the local language it does not have to be completed, Clarification that the recommendations for the volume of blood collected relate to the research specific bloods, Addition of Section 1.6 related to the benefit-risk assessment for the trial, Addition of ‘or known phenylketonuria to aspartame used in a formulation in an infant less than 12 weeks.’ to exclusion 7. criteria, Rationale for collecting date of birth added, The details regarding collection of weight for dosing has been moved from 5.3.1 to 5, Clarification that there are no trial specific temperature monitoring requirements for the IMP, Inclusion of a +/- 20% flexibility in the dosing of IVIG and aspirin, Removal of wording surrounding the regular weight collection included in error, Clarification that enough IMP should be dispensed to reach the participants next visit or to allow the completion their duration of corticosteroids, Addition of mitigation for provision o

EudraCT number added to cover and general information, Addition of (Fortaleza, Brazil, October 2013) to the Declaration of Helsinki meeting which the trial is run in accordance with, Update to MRC CTU staff, Update to exclusion criteria 10 to include active influenza infection, Removal or wording ‘In particular, the investigator must ensure that the children’s anonymity will be maintained and that their identities are protected from unauthorised parties.’, Update from a Standard Operating Procedure to Guidance, Update wording in section 9.4 to make it consistent with the wording changed in Protocol v4.0, Oversight and Trial Committees Section