Kawasaki disease and multisystem inflammatory syndrome following SARS-CoV-2 vaccination; Kawasaki disease and multisystem inflammatory syndrome following SARS-CoV-2 vaccination; This is a literature report.  A man in his 40s presented to the hospital complaining of 1 day of fever, sore throat, abdominal pain associated with loose stools and a diffuse erythematous rash. The rash was non-tender, non-pruritic, blanching, and had progressed from his right thigh to include diffuse areas of his chest, abdomen, back, and the palms and soles of his hands and feet. He denied prodromal symptoms prior to the onset of rash and denied prior COVID-19 infection. He received the second dose in a two-dose series of the Pfizer-BioNTech mRNA SARS-CoV-2 vaccine approximately 4 weeks prior to the onset of symptoms. A SARS-CoV-2 RNA reverse transcriptase (RT)-PCR assay of a nasopharyngeal swab specimen was negative. A presumptive diagnosis of bacterial pharyngitis was considered and throat specimens were obtained for culture. He was prescribed a short course of oral amoxicillin and released without hospital admission. Three days later, the patient returned to the hospital complaining of persistent fever, sore throat, non-productive cough, ongoing abdominal pain and loose stools, worsening rash, and new-onset painful joint swelling in the hands and feet. He reported full compliance with recently prescribed amoxicillin. On further questioning, the patient denied chronic medical conditions and reported no known allergies to medications or environmental allergens. He denied family history of autoimmune or inflammatory disease and denied recent contact with sick individuals or individuals exposed to SARS-CoV-2. He denied recent travel, recent outdoor activities, or exposure to wildlife or livestock. He denied intravenous drug use, new sexual partners or a history of tattoos. He denied use of tobacco products, alcohol or illicit substances, and stated that he does not use medications or supplements regularly. He did not know details of prior vaccinations though denied adverse reactions to vaccines in the past. Examination revealed extension of the erythematous rash to encompass both thighs and approximately half of the torso and chest surface. Symmetric involvement of the palms and soles of the hands and feet was present. Conjunctival injection without exudate was present bilaterally and oral examination revealed angular cheilitis, erythematous strawberry tongue, dry mucous membranes without ulceration and enlarged tonsils without exudate. Diffuse cervical lymphadenopathy was present. Joint examination revealed bilateral shoulder pain on passive range of motion testing, swelling and tenderness in bilateral wrists, bilateral proximal phalangeal joints associated with inability to make a fist, bilateral ankles and bilateral metatarsophalangeal joints associated with difficulty walking. Empiric antibiotic therapy with oral doxycycline was initiated on the first day of hospitalisation. Symptoms persisted despite antibiotic treatment, including fever to a maximum temperature of 38.9°C. 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. 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. 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: Considering the absence of alternative explanations, the temporal relationships between symptom onset and vaccination, and the isolated elevation in spike protein antibody levels without evidence of concurrent or prior SARS-CoV-2 infection, a postvaccination inflammatory syndrome presenting as KD and meeting criteria for MIS-V appears most likely. Importantly, temporal association between inflammatory syndromes and vaccination is not tantamount to causation. Vaccine hesitancy that results from misattribution of rare inflammatory syndromes to vaccination may indeed blunt the use of an essential tool in the battle against COVID-19. Thorough investigation of temporally related events, as presented in this report, and ongoing efforts to support widespread vaccination against SARS-CoV-2 are critical to safely and effectively combating COVID-19. Nonetheless, early recognition and intervention may limit progression in both MIS and KD and may forestall the development of cardiac dysfunction after KD. As widespread vaccination against SARS-CoV-2 continues, increased vigilance and prompt intervention is necessary to limit the effects of rare postvaccination inflammatory syndromes.; Sender's Comments: Based on the current available limited information in the case provided, the causal association between the events Kawasaki's disease and Multisystem inflammatory syndrome and the use of suspect product BNT162B2 cannot be fully excluded. The case will be reassessed once further information is available The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to RAs, Ethics Committees, and Investigators, as appropriate.