very large rash all over his arm; Headache; Joint pain; super itchy; It was his left arm like red; It was his left arm ache; left arm like swollen; This is a spontaneous report received from a contactable reporter(s) (Pharmacist) from medical information team.  A 58-year-old male patient received bnt162b2 (BNT162B2), administration date 23Sep2021 (Batch/Lot number: unknown, Expiration Date: 31Oct2021) at the age of 58 years as dose 1, single for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported.   The following information was reported: RASH (non-serious) with onset 2021, outcome "unknown", described as "very large rash all over his arm"; HEADACHE (non-serious) with onset 2021, outcome "unknown", described as "Headache"; ARTHRALGIA (non-serious) with onset 2021, outcome "unknown", described as "Joint pain"; PRURITUS (non-serious) with onset 2021, outcome "unknown", described as "super itchy"; ERYTHEMA (non-serious) with onset 2021, outcome "unknown", described as "It was his left arm like red"; PAIN IN EXTREMITY (non-serious) with onset 2021, outcome "unknown", described as "It was his left arm ache"; PERIPHERAL SWELLING (non-serious) with onset 2021, outcome "unknown", described as "left arm like swollen". Therapeutic measures were taken as a result of erythema, pain in extremity, peripheral swelling.  Additional information: Caller states they had a patient walk in with a very large rash all over his arm, and it has been about a week from receiving his first vaccine. Caller asks for guidance for what to do in terms of the second one. Read from attached FAQ-COVID-19 Vaccine-receiving second dose after side effect from first dose (v2.0). Transferring agent stated, "I have a pharmacy student intern on other line reporting an AE for the Pfizer BioNTech COVID-19 vaccine and as I said before she is a pharmacy student intern (Hence, captured as consumer or Other Non-HCP). She said they have a patient that have very large rash all over his arm and it's been about a week from receiving his 1st vaccine. Reporter was informed about Pfizer drug safety department and its role. Height and weight: Reporter stated, "I am not sure if we have the height and weight in the system, I am just double checking. Ethnicity: Reporter stated, I believe Caucasian. Start date of adverse event: Reporter stated, "Yeah and I submitted, the patient received his 1st dose of Pfizer COVID-19 vaccine on 32Sept, one day after I am trying to remember because I submitted a report through wavers, I believe FDA adverse event report. He came to our pharmacy initially earlier last week describing he had some red itchy dot on his arms and leg and he had like a headache, some joint pain and nothing seems to help, the pharmacist on duty recommended some over the counter some allergy medication, I think it must be Zyrtec, Claritin and then Benadryl (further clarification unknown) was needed at the night time and that was the day, I can't remember which day it was but I submitted the adverse event report and then today the patient came in and his whole arm I believe, it was his left arm like red, swollen ache, went to the doctor I think he is on prednisone (Treatment) now super itchy so that's where we are now. Reporter stated expiry date 31Oct2021 but not sure (Further not clarified hence, not captured in tab). Reporter stated, "He was recommended the over the counter antihistamine and he is currently taking prednisone and I am not sure half back what else he tried."  Follow-up attempts completed. No further information is expected.