annoying almost pain; She woke up and her cheeks were red; Initially the rash began with her legs itching; Rash she experienced with the second booster dose or her fourth dose of Pfizer Vaccine for Covid; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 75-year-old female patient received BNT162b2 (BNT162B2), on 31Mar2022 at 12:30 as dose 4 (booster), single (Lot number: FK9894) at the age of 75 years, in left arm for covid-19 immunisation. The patient had no relevant medical history. The patient took concomitant medications. Patient reported no relevant concomitant product use or other medical conditions for this report. She explained she is taking nothing new, she takes some medications and a bunch of vitamins, but nothing new and nothing changed. Vaccination history included: BNT162b2 (Dose 1, Lot: EL1284, NDC/Expiry: Unknown, not on the CDC vaccine record card., Dose: Unknown/strength/dose, not on the CDC vaccine record card), administration date: 14Jan2021, when the patient was 73-year-old, for COVID-19 Immunization; BNT162b2 (Dose 2, Lot: EL9264, NDC/Expiry: Unknown, not on the CDC vaccine record card., Dose: Unknown/strength/dose, not on the CDC vaccine record card), administration date: 04Feb2021, when the patient was 73-year-old, for COVID-19 Immunization; BNT162b2 (Dose 3, Lot: EW0787, NDC/Expiry: Unknown, not on the CDC vaccine record card., Dose: Unknown/strength/dose, not on the CDC vaccine record card.), administration date: 17Aug2021, when the patient was 74-year-old, for COVID-19 Immunization. No other vaccines administered on same date with the Pfizer vaccine considered as suspect. No other vaccinations within four weeks prior to the first administration date of the suspect vaccine. The following information was reported: RASH (medically significant) with onset 31Mar2022, outcome "recovering", described as "Rash she experienced with the second booster dose or her fourth dose of Pfizer Vaccine for Covid"; PRURITUS (non-serious) with onset 02Apr2022, outcome "recovering", described as "Initially the rash began with her legs itching"; ERYTHEMA (non-serious) with onset 02Apr2022, outcome "recovering", described as "She woke up and her cheeks were red"; PAIN (non-serious) with onset 03Apr2022, outcome "unknown", described as "annoying almost pain". The events "rash she experienced with the second booster dose or her fourth dose of pfizer vaccine for covid", "initially the rash began with her legs itching", "annoying almost pain" and "she woke up and her cheeks were red" required physician office visit. Therapeutic measures were taken as a result of rash, pruritus, pain, erythema. This reporter is a Psychotherapist Social Worker who is also the patient. She called to report rash she experienced with the second booster dose or her fourth dose of Pfizer Vaccine for COVID. Rash: Allergic reaction rash. Time of onset: Nighttime. Initially the rash began with her legs itching, she thought she might have a bite or poison ivy; but then she continued to get more of what she thought was a couple of bites which then spread on her arms and then it spread into a rash.By Friday afternoon, 01Apr2022 it was a rash. Saturday morning, 02Apr2022 she woke up and her cheeks were red, then throughout the day it kept getting redder and redder and really a rash so that you could feel that it was a little bit something, not smooth skin and horrible horrible itching. Saturday and Sunday night, 02Apr2022 and 03Apr2022 she kept waking up every 2 hours to itching and annoying almost pain. As soon as she could get an appointment on Monday morning, 04Apr2022 she went to her primary care provider's office and had appointment with the Physician Assistant. The Physician Assistant gave her a cortisone shot and prescribed the Hydroxyzine HCl for the rash. She did not pick up or start the Hydroxyzine HCl until 05Apr2022. Once she had been administered the cortisone shot, every hour, by that time her legs were getting better. By every hour her face was getting less angry and red, arms getting better, and she went to sleep with no more itching. On Tuesday, 05Apr2022 the rash was practically going away. She was taking those very low dose benadryls at night, not much-she then clarified that she was not actually taking Benadryl, it was Hydroxyzine HCl 50mg tablets, and she only took 2 of those tablets total. Today, 11Apr2022 she saw someone who was not a physician and they said it looks like she has had a chemical peel which she has never had. She looked it up on the internet. It said uncommon side effect is a rash, but they didn't identify Pfizer or Moderna. She is fine, but thought it might be useful to report. She feels great yesterday and today. Regarding outcome: Caller initially reported as totally recovered for a few days; but then clarified as improved: skin on her face and arms are still having a little peeling from the rash. Legs not that she noticed, but her face was a little bit more than arms; and also her left arm where got the shot is a little bit more than right. Patient just felt that she had a side effect that was very unusual for her. Cortisone shot: Lot/NDC/Expiry: unknown, given at doctor's office. Hydroxyzine HCl: Lot/NDC/Expiry: Unknown, dispensed in standard pharmacy bottle. She stopped taking Hydroxyzine HCl because she does not really need it and is feeling better, they told her it maybe would make her sleepy; thought she would save it for when she is doing gardening and has poison ivy in the future. She was told that in # when people went for a COVID test, she guessed that if it came back positive on the spot they gave them the medication to nip it in the bud; and she thought wow, that is a brilliant idea; but in # she does not think they're doing that yet. #. So Pfizer has one of those medications she thinks. Relevant Tests: None, pretty knockwood healthy bunch, very active and healthy.