SARS-CoV-2 spike protein antibody levels have been used in prior investigations to assess the immune response to vaccination,22 particularly when accompanied by the absence of SARS-CoV-2 nucleocapsid antibodies and the absence of viral RNA detected by RT-PCR to exclude prior or concurrent infection

SARS-CoV-2 spike protein antibody levels have been used in prior investigations to assess the immune response to vaccination,22 particularly when accompanied by the absence of SARS-CoV-2 nucleocapsid antibodies and the absence of viral RNA detected by RT-PCR to exclude prior or concurrent infection.23 While KD has been described following SARS-CoV-2 infection in adults and children,20 24 25 only one prior report documents KD following vaccination against SARS-CoV-2.26 That man in his teens experienced symptoms 3?weeks after the first dose of a SARS-CoV-2 vaccine and similarly responded to treatment with IVIg. postvaccination inflammatory syndromes. IgG (titre) 1:64 1:64?IgG (titre) 1:64 1:64?Lyme antibody EIANegativeNegative?Rapid plasma reagent screenNon-reactiveNon-reactive?IgG (titre) 1:64 1:64?IgM (titre) 1:64 1:64?Rapid plasma reagent??CMV IgG EIAPositiveNegative??CMV IgM (AU/mL) 8.0 29.9??EBV VCA IgG (units/mL) 7500.0C21.9??EBV VCA IgM (units/mL) 10.00.0C43.9??Heterophile antibody assayNegativeNegative??HIV 1/2 antibody & p24 antigen screen (fourth generation)Non-reactiveNon-reactive??Quantiferon gold IGRANegativeNegative??Hepatitis B surface antibody (mIU/mL)72.0 8.0??Hepatitis B surface antigen EIANon-reactiveNon-reactive??Hepatitis C antibodyNon-reactiveNon-reactive?Blood cultureNo growthNo growth?Urine cultureNo growthNo growth Open in a separate window Treatment Daily aspirin and a 3?day course of IVIg were initiated on the second day of hospitalisation. Over the ensuing 6?days sustained defervescence and progressive abatement of rash were observed, marked by desquamation of the palms and soles (figure 2). Reduced swelling and return of full range of motion in the joints of hands and feet accompanied resolution of the rash. Tongue erythema and conjunctival injection resolved over a period of 5?days following initiation of IVIg. Oral prednisone was initiated on the fifth day, following completion of IVIg. Open in a MOBK1B separate window Figure 2 Desquamation of the hands and feet during resolution of rash (A, B). Outcome and follow-up Laboratory analysis on the fifth day of hospitalisation revealed reduced inflammatory markers and mild thrombocytosis that peaked on the seventh day. A transthoracic echocardiogram performed on the second day revealed no evidence of cardiac dysfunction, and CT coronary angiogram performed on the seventh day did not demonstrate coronary aneurysms or stenosis. On discharge from acute care on the seventh day of hospitalisation, the patient reported significant improvement in symptoms including complete resolution of fever, joint pain, abdominal pain and erythematous rash. Painless desquamation of the palms and soles of the hands and feet was present. The patient was instructed to continue daily aspirin and complete a taper of oral prednisone over 3?weeks. One month after discharge the patient reported sustained resolution of symptoms, though did demonstrate ongoing painless desquamation of the palms and soles. Two months after discharge the patient reported resolution of desquamation. Laboratory analysis revealed resolution of thrombocytosis and normalisation of inflammatory markers. Results of a serum assay revealed an extremely high concentration of SARS-CoV-2 spike protein antibodies. Discussion We report a man that demonstrated symptoms consistent with KD and concerning for MIS-V 4?weeks after the second dose of the Pfizer-BioNTech mRNA SARS-CoV-2 vaccine. No evidence of concurrent or prior SARS-CoV-2 infection was detected, though high levels of antibodies against the SARS-CoV-2 spike protein, measured to assess immune response to vaccination, were detected. Extensive investigation did not reveal evidence of an alternative aetiology and resolution of symptoms followed courses of IVIg and oral prednisone. MIS is a rare response to SARS-CoV-2 exposure in children and adults. The recently proposed Brighton Collaborative case definition of MIS notes similarities to KD, and establishes levels of diagnostic confidence based on presence of persistent fever, multiorgan dysfunction, hypotension, DCVC elevated serum inflammatory markers, confirmed exposure to SARS-CoV-2, or within 12 weeks of vaccination if known exposure has not occurred.10 This patient presented with persistent fever over 5?days, mucocutaneous and gastrointestinal symptoms, elevated liver enzymes, microscopic haematuria, elevated inflammatory markers, and recent SARS-CoV-2 vaccination without known or suspected SARS-CoV-2 exposure. No compelling alternative aetiology was identified and prompt improvement in symptoms and disease markers followed treatment with IVIg and steroids. Therefore, by current criteria this patient may be DCVC classified as probable MIS-V. Development of symptoms approximately 4C6? weeks following exposure and response to IVIg are consistent with prior reports of MIS in DCVC adults.10 13 This patient did not experience severe organ dysfunction and did not require intensive care; therefore, he experienced a comparatively milder condition than those previously reported. Early administration of IVIg resulted in prompt improvement and may have prevented progression to a more severe condition. In addition to probable MIS-V, this patients presentation and clinical course met criteria for the diagnosis of KD. At the time of hospital admission, he had.