anaphylactic reaction; severe rash on my back; erythema unrelenting itch / erythema; erythema unrelenting itch / Severe itch / itching spreading lesions / pruritis; urticaria; severe drug reaction / allergic reaction; received the third dose of the Pfizer Covid 19 Vaccine; received the third dose of the Pfizer Covid 19 Vaccine; This is a spontaneous report from a contactable physician, reporting for himself.  A 62-year-old male patient received bnt162b2 (BNT162B2), dose 3 via an unspecified route of administration, administered in Arm Left on 17Aug2021 at 13:00 (Batch/Lot Number: FC3181) as DOSE 3, SINGLE for covid-19 immunisation; and influenza vaccine inact split 4v (AFLURIA QUAD), via an unspecified route of administration from 17Aug2021 at 13:00 (Batch/Lot Number: P100344370), at DOSE NUMBER UNKNOWN, SINGLE for flu prevention.  Medical history included osteoarthritis from 2001 and ongoing (from: 20 years ago), shoulder replacement from 02Aug2021, gastrooesophageal reflux disease from 1981 and ongoing (from 40 years), penicillin allergy that causes a non significant rash (he had it at the age of 12), and cephalosporin use from an unspecified date. Concomitant medication(s) included acetylsalicylic acid (ASPIRIN N) taken for stroke prevention from 2016 and ongoing; famotidine (PEPCID AC) taken for dyspepsia from 2001 and ongoing; omeprazole (ZEGERID [OMEPRAZOLE]) taken for dyspepsia, gastrooesophageal reflux disease from an unspecified start date and ongoing; cefazolin sodium (ANCEF [CEFAZOLIN SODIUM]) taken for an unspecified indication, start and stop date were not reported; vitamin b12 nos (VITAMIN B12 NOS) taken for an unspecified indication from Feb2021 and ongoing; vitamin d3 (VITAMIN D3) taken for an unspecified indication from Feb2021 and ongoing; multivitamins [vitamins nos] (MULTIVITAMINS [VITAMINS NOS]) taken for an unspecified indication from Feb2021 and ongoing; xantofyl (LUTEIN) taken for an unspecified indication from Feb2021 and ongoing; omega-3 nos (OMEGA-3 NOS) taken for an unspecified indication from Feb2021 and ongoing; monascus purpureus (RED YEAST RICE) taken for an unspecified indication from Feb2021 and ongoing; chondroitin sulfate sodium, glucosamine hydrochloride (OSTEO-BI-FLEX) taken for an unspecified indication, start and stop date were not reported.  The patient experienced severe rash on his back on 18Aug2021 with outcome of not recovered, erythema unrelenting itch / erythema on 18Aug2021 with outcome of not recovered, erythema unrelenting itch / severe itch / itching spreading lesions / pruritis on 18Aug2021 with outcome of not recovered, urticaria on 18Aug2021 with outcome of not recovered, severe drug reaction / allergic reaction  on 18Aug2021 with outcome of not recovered, anaphylactic reaction at 7 AM on the 18Aug2021 with outcome of not recovered and received the third dose of the pfizer covid 19 vaccine on 17Aug2021 with outcome of unknown.  The patient underwent lab tests and procedures which included biopsy skin: consistent with allergic reaction on 20Aug2021. Details were reported as follows: he had a severe rash on his back, erythema unrelenting itch, pruritis. He called his dermatologist, waited 2 days to see him. It Spread to his upper back, butt, thighs, legs, and upper arms. He is taking 50mg prednisone everyday with taper, Clobetasol steroid cream in addition, 20 mg Zyrtec took in the am and 50mg Benadryl at night. this is the tapered down amount, he was taking more. Rash improved over next few days, and as of right now he has noticed that over several days it has improved but he is getting spontaneous corn lesions over his body, in spite of his taking of antihistamine and prednisone. Dermatologist is at a loss, the only thing he did differently was taking the flu vaccine and could be either one of the vaccines or both. The flu shot was offered at the same time as his third dose of Pfizer covid 19 vaccine and he took them both at the same time. He was given high dose steroids, Prednisone taper, Zyrtec, Benadryl and Clobetasol.; Sender's Comments: Based on the current limited available information and the drug-event temporal association, a possible contributory role of the suspect product BNT162B2 to the development of events rash, erythema, pruritus,  urticaria, drug hypersensitivity and anaphylactic reaction cannot be totally excluded/assessed.  The case will be reassessed if additional information becomes 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 regulatory authorities, Ethics Committees, and Investigators, as appropriate.