rash has appeared more on her back as of last week/horrible rash worsened; This is a spontaneous report received from a contactable consumer (patient). A 50-year-old female patient received second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE; Solution for injection; Lot number: unknown) via an unspecified route of administration in left arm on 26Mar2021 at 09:15 (at the age of 50-year-old) as single dose for COVID-19 immunization. Medical History of the patient included seasonal allergies [lifelong, ongoing] and patient was very prone to pneumonia [from about 22 years ago]. It usually starts with seasonal allergies, then becomes respiratory infection and then she ends up with pneumonia. Family Medical History included none. Concomitant/other Products included Cetirizine HCl (Start: Unknown Stop: Unknown) taken for seasonal allergies. Patient had no prior Vaccinations (within 4 weeks) or any vaccination on the same date of COVID-19 vaccine. Patient previously received first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE; Solution for injection; Lot number: unknown; NDC: 59267-1000-01) via an unspecified route of administration in left arm on 04Mar2021 (at the age of 50-year-old) as single dose for COVID-19 immunization and experienced horrible rash. On an unspecified date after second dose of vaccination the rash came back within days, only more on her torso and sides. The rash has appeared more on her back as of last week, does not itch or hurt, but it was very distressing to see. Patient stated on Sunday, she was advised to see a HCP in which she went to an urgent care. The physician at urgent care told her to continue taking Claritin and Benadryl and suggested hydrocortisone cream and to take 1 Pepcid twice a day for H2 blocker. She took 2 Claritin and 1 Pepcid in the morning and 1 Benadryl and 1 Pepcid in the evening. She has not gotten any better. Patient asked if this was a common reaction and if she was treating the rash correctly. Reportedly, after the second dose of Pfizer-BioNTech Covid-19 Vaccine the horrible rash worsened. Horrible rash was on her torso and back, nowhere else. The horrible rash had areas where some are bigger, some are smaller, but she still has them. Poison control kept calling her like every 3 days asking how she was. She was telling them the same, no pain, nothing, just kind of embarrassing so she was glad no one can see it. This past Sunday, 11Apr2021 poison control advised her to go see her doctor. Her primary care doctor was not available so she went to a local urgent care on Monday, 12Apr2021 and they agreed the horrible rash probably is definitely a reaction to the Pfizer-BioNTech Covid-19 Vaccine and to continue what she was doing, taking the Loratadine [Loratadine: 10mg tablet. Lot: Does not say Lot, but above the expiry is: 1BE2281A, Expiry: Nov2022, Below the expiry is: 61272 2E F5, NDC: Caller asked could they make this any smaller, she already had glasses on: She initially thought it had two threes: 490335 but clarified she believes it just has one three: 49035-612-72. UPC: Unknown]and Diphenhydramine HCl [Diphenhydramine HCl: Pharmacy brand: 25mg tablet nightly, NDC: 49035-929-12, Lot: provided number above the Expiry: P123716, Expiry: Jan2023, UPC: Unknown], and to start taking some Pepcid so she was still taking generic for Pepcid: Famotidine [Famotidine: 20mg daily. Caller reported the NDC was a tiny number on the product: NDC: 49035-650-71, Expiry: Sep2022, Lot: Unknown, but she provided the numbers above and below the expiry: Above: 0ME2195B, Below: 19471 2E F8, UPC: Unknown] for the horrible rash started Monday, 11Apr2021. She later mentioned they also recommended that she start applying Hydrocortisone cream to the affected area of the horrible rash even though she is not itching, so she has been applying Hydrocortisone [Hydrocortisone cream: NDC: 49035-973-27, Lot: AC14770, Expiry: Dec2023, UPC: Unknown] cream as recommended. The horrible rash still hasn't gotten better. The coloring of the horrible rash was a little better, it's lighter in color, but she has more areas of the horrible rash, more on her back than she did before but it has worsened since onset and then stayed the same pretty much at that worsened point since. She feels fine, the horrible rash just looks ugly. Patient was advised to stop the Cetirizine HCl and switch to Claritin, which she started generic formulation of: Loratadine. They advised her to switch because of something about the Zyrtec or Cetirizine HCl inhibitor. She has also taken the new Dual-Action Advil with Acetaminophen as needed: NDC/UPC: Unknown, caller does not have the box the product came in, there is no NDC/UPC on the product itself, Lot: Unknown, but number above the Expiry is DN7578, Expiry: Mar2023, and unknown number: PAA 117206. Outcome of the event was not resolved.  No follow-up attempts are needed. No further information is expected.