They found was roseola and it is a reaction to the Pfizer booster; I am having a horrible adverse reaction to this; I had allergic reaction to your medication (COVID-19 Vaccine); I started getting itchy red patches, welts and hives; it continued to get worse; I started getting itchy red patches, welts and hives; it continued to get worse; I started getting itchy red patches, welts and hives; it continued to get worse; I started getting itchy red patches, welts and hives; it continued to get worse; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non-HCP). The reporter is the patient.  A patient (no qualifiers provided) received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 04Jan2023 as dose 5 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Covid-19 vaccine (DOSE 4; MANUFACTURER UNKNOWN), for COVID-19 immunization; Covid-19 vaccine (DOSE 3; MANUFACTURER UNKNOWN), for COVID-19 immunization; Covid-19 vaccine (DOSE 2; MANUFACTURER UNKNOWN), for COVID-19 immunization; Covid-19 vaccine (DOSE 1; MANUFACTURER UNKNOWN), for COVID-19 immunization. The following information was reported: HYPERSENSITIVITY (non-serious) with onset Jan2023, outcome "unknown", described as "I had allergic reaction to your medication (COVID-19 Vaccine)"; PRURITUS (non-serious), URTICARIA (non-serious), CONDITION AGGRAVATED (non-serious) all with onset Jan2023, outcome "not recovered" and all described as "I started getting itchy red patches, welts and hives; it continued to get worse"; ERYTHEMA (non-serious) with onset Jan2023, outcome "unknown", ROSEOLA (non-serious) with onset Jan2023, outcome "unknown" and all described as "They found was roseola and it is a reaction to the Pfizer booster; I am having a horrible adverse reaction to this". The events "they found was roseola and it is a reaction to the Pfizer booster; I am having a horrible adverse reaction to this", "I had allergic reaction to your medication (covid-19 vaccine)" and "I started getting itchy red patches, welts and hives; it continued to get worse" required physician office visit.  Additional information: It was reported that on the 04Jan of this year patient received a Pfizer third booster shot for COVID (Clarified as Pfizer COVID-19 Vaccine) within two days patient started getting itchy red patches, welts and hives consulted with the doctor and could not really conclude too much about it, but it continued to get worse. So, went back to what patient had been exposed to and one of the things was the COVID Vaccination. So, they checked it, and they are on the hold. What they found was roseola probably was roseola and it was a reaction to the Pfizer booster. Patient understand there already been a couple reported felt this necessary to report the fact that patient was having a horrible adverse reaction to this." Patient was at urgent care now, stated could I have to call return maybe tomorrow because it was difficult for me to understand you and I am in pain I want to go home and take drug and lay down and go to sleep.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.