he then developed red man syndrome; a suspected reaction to the antibiotic; Patient then developed a speckled red rash across his chest; The doctor thought patient had a MRSA infection; injection site increasing redness and swelling; injection site increasing redness and swelling, his affected arm continued to have increasing swelling; Initial information was received on 05-Apr-2021 regarding an unsolicited valid serious case from a consumer or non-healthcare professional.  This case involves a seven-year-old male patient who experienced injection site increasing redness and swelling (injection site erythema and injection site swelling) and the doctor thought patient had a mrsa infection (staphylococcal infection), a speckled red rash across his chest (rash erythematous), he then developed red man syndrome (red man syndrome) and a suspected reaction to the antibiotic (adverse drug reaction) while he received INFLUENZA QUADRIVAL A-B VACCINE [FLUZONE QIV].  Medical history, medical treatment, vaccination, concomitant medication and family history were not provided.  On 29-Oct-2010, the patient received a dose of suspect INFLUENZA QUADRIVAL A-B VACCINE [lot number and expiry date not reported] via an unknown route at an unknown administration site for prophylactic vaccination.  The doctor thought patient had a MRSA infection so administered antibiotics, reporter thinks clindamycin.  Reporter reporting she then brought her son back to the hospital on 01-Nov-2010, when he was admitted overnight with a suspected reaction to the antibiotic. He was then given, she thinks Vancomycin, he then developed red man syndrome.  On 29-Oct-2010, the patient developed a serious injection site increasing redness and swelling (injection site erythema and injection site swelling) and the doctor thought patient had a mrsa infection (staphylococcal infection) on the same day following the administration of INFLUENZA QUADRIVAL A-B VACCINE. These events were assessed as medically significant. The patient was hospitalized for these events.  On an unknown date, the patient developed a serious patient then developed a speckled red rash across his chest (rash erythematous), he then developed red man syndrome (red man syndrome) and a suspected reaction to the antibiotic (adverse drug reaction) unknown latency following the administration of INFLUENZA QUADRIVAL A-B VACCINE. These events were assessed as medically significant. The patient was hospitalized for these events.  Details of laboratory data were not reported.  It was not reported if the patient received a corrective treatment.  At the time of reporting, the patient is recovered from injection site erythema and injection site swelling, and the outcomes of staphylococcal infection, rash erythematous, red man syndrome and adverse drug reaction were unknown.  Information on the batch number is requested.; Sender's Comments: This case involves a seven-year-old male patient who experienced injection site erythema (latency:1 day), injection site swelling (latency:1 day), staphylococcal infection (latency:1 day), rash erythematous (unknown latency), red man syndrome (unknown latency) and adverse drug reaction (unknown latency) after vaccination with INFLUENZA QUADRIVAL A-B VACCINE [FLUZONE QIV]. The time to onset was compatible. Further information regarding concurrent condition during vaccination, previous vaccination and tolerance, laboratory investigations excluding alternative etiologies for the reported event are needed to fully assess this case. Based upon the reported information, the role of the suspect vaccine cannot be assessed.