Swollen arm; Injection site red and hot to touch and very sore; injection site is 3 times bigger than it was before; Injection site red and hot to touch and very sore; injection site is 3 times bigger than it was before; Injection site red and hot to touch and very sore; injection site is 3 times bigger than it was before; Injection site red and hot to touch and very sore; injection site is 3 times bigger than it was before; Headache; Body ache/arm from the shoulder to the elbow looks normal it was achy; cellulitis; This is a spontaneous report from a contactable consumer (patient). An 83-year-old female patient received second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Solution for injection, lot number: EN6201, Expiry date: Jun2021) via unknown route of administration on 21Feb2021 10:30 AM at single dose for prevention/COVID-19 immunisation. Medical history included LBBB (bundle branch block left, heart problem), osteoarthritis, thyroid (patient was taking thyroid medications, thyroid elevated), chronic lymphoma leukaemia (that has been initiated for 9 years), slight heart problem. Concomitant medications included ongoing furosemide (strength: 10 mg) 10 mg once a day and amlodipine (strength: 10 mg) 10 mg once a day. The patient previously took first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, lot number: EL8982, Expiry date: May2021), via an unspecified route of administration on 31Jan2021 (at age of 83-year-old) for COVID-19 immunisation and experienced sore arm. It was reported that patient stated, on 22Feb2021 Monday morning I woke up about 2:00 AM with a headache and all over body ache, on Tuesday I felt a little better, on 23Feb2021 the injection site red and hot to touch and very sore, injection site is 3 times bigger than it was before, on 24Feb2021 Wednesday my arm quite swollen, so I had an appointment with my primary care, they prescribed antibiotics 'Streptomycin' (not clear) 500 mg. This was my 3rd day and my arm was still swollen now 3 times more it was before and very sore." Consumer added, "My left hand was also swollen but since I have been on antibiotics that has gone down. By the 24Feb2021 her arm had about the size of a half dollar, a big red spot that was sore and she went to her primary care who gave her an antibiotic called Cephalexin and 2 days later she couldn't get back in there, because there were no doctors available so she went to the Emergency Room which was 30 miles from where they live and they increased the Cephalexin from 2 times per day the 3 times per day and added Bactrim to it as well so she did that for 2 days and then on the 28Feb2021 she went back to the ER because it kept getting bigger and bigger and it was almost down to her elbow and so then they sent her and they admitted her into a ER observation and she stayed there for 3 days and they gave IV Clindamycin and she came home on the 03Mar2021 with 7 more days of Clindamycin to take orally. She has the Cephalexin she had already put them in the bag to be recycled she had just a few tablets left. She sees NDC 67877-0219-05, it says beyond use 27Feb2022 she does not see lot number on the pharmacy vial. It says plan DSER and she sees Ascend labs. On the Bactrim vial it says NDC 65162-0272-10. It was also in a pharmacy vial. It says beyond use 25Feb2022. The Clindamycin IV she received in the hospital. She has the Clindamycin tablets they sent her home with. The Clindamycin is also in a pharmacy vial she does not see lot number. NDC 65862-0185-01 and it says beyond use 03Mar2022. The diagnosis was cellulitis in 2021. She clarifies she first noticed the red spot on her 23Feb2021 it was about the size of a quarter, on the 24Feb2021 it was larger and she went to her primary. It was ongoing but at this point she was a couple days into the antibiotic and the arm from the shoulder to the elbow looks normal it was achy this morning when she woke up at 4am but she was now hoping she was on her way. She was in pretty good health overall. For events vaccination site erythema, vaccination site pain, vaccination site warmth, vaccination site swelling and peripheral swelling seriousness criteria was reported as hospitalization from 28Feb2021 to 03Mar2021 and patient went to emergency room for vaccination site erythema, vaccination site pain, vaccination site warmth, vaccination site swelling and peripheral swelling. The outcome of events headache and general body pain was recovering, cellulitis was unknown and for rest of the events was not recovered.  No follow-up attempts are possible. No further information is expected.