On the inner elbow of left arm she is having a little discomfort; The second evening she had throbbing pain like a hot throbbing pain.; booster; She had a 4 inch bright red welt on her arm/ now has a 2 inch pink colored welt across the arm; She had a 4 inch bright red welt on her arm; Heat coming from area/ It was very hot; It is still swollen; She had discomfort just above the shoulder blades radiating from the area where she had the booster; This is a spontaneous report from a contactable other health care professional (patient). A 86-years-old female patient received third dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection, lot number was not reported), via an unspecified route of administration, administered in left arm on 03Nov2021 16:30 (at the age of 86 years) as dose 3 (booster), single for COVID-19 immunization. The patient medical history included a little temperature a couple of years ago with the flu shot. The patient concomitant medications included cyanocobalamin (VITAMIN B12 [CYANOCOBALAMIN]) shots that were given in the right arm on 02Nov2021. The patient previously received first dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection, lot number was not reported), via an unspecified route of administration, administered in left arm on Jan2021 (at the age of 85 years) as dose 1, single and received second dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection, lot number was not reported), via an unspecified route of administration, administered in left arm on Feb2021 (at the age of 85 years) as dose 2, single both for COVID-19 immunization. Additional vaccines administered on same date of the pfizer suspect were none. The patient mentioned she had a terrible reaction to the Covid19 booster shot. Early in the evening on 03Nov2021 the patient experienced she had a 4 inch bright red welt on her arm. On 04Nov2021 (the second evening) she had throbbing pain like a hot throbbing pain. On 10Nov2021 the patient had on the inner elbow of left arm she is having a little discomfort. On an unspecified date in Nov2021 the patient had heat coming from area, it is still swollen, it was very hot with, she had discomfort just above the shoulder blades radiating from the area where she had the booster. That didn't last too long. It lasted two days. It wasn't constant, it was intermittent. On an unspecified date in Nov2021 the welt on her arm is starting to get smaller. It has been 8 days and now has 2 inch pink colored welt across the arm. The events did not require emergency room or physician office visit. On an unspecified date she took two extra strength paracetamol (Tylenol, Lot number: MFA101; Expiration date: May2020; strength: 500 mg) as therapeutic measures were taken as a result of the second evening she had throbbing pain like a hot throbbing pain and that didn't stop the pain. There was no investigation assessment. Reporter seriousness for bright red welt on her arm, Throbbing pain was reported as Medically significant. The outcome of the event discomfort just above the shoulder blades was resolved on an unspecified date in Nov2021. The outcome for event inner elbow of left arm she is having a little discomfort was unknown. The outcome for event throbbing pain, heat coming from area/ it was very hot, it is still swollen not resolved. For the rest of the events the outcome was resolving.  Relatedness of drug to reaction(s)/event(s): Reaction assessed: bright red welt on her arm, Throbbing pain and heat coming from area. Source of assessment: Primary Source Reporter. Method of assessment: Global Introspection. Drug result: Related.  The lot number for the vaccine, [BNT162B2], was not provided and will be requested during follow up.; Sender's Comments: Based on the information provided in the narrative, a causal association between the suspect drug and the events Urticaria, Erythema, Pain , cannot be completely excluded. The impact of this report on the benefit/risk profile of the product is evaluated as part of 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.