big lump under her armpit on her left arm where she got the shot and she has very much discomfort there; that area was just burning; itching sensation; she could not sleep on it on that side; it was just very uncomfortable; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 39 year-old female patient received bnt162b2 (BNT162B2), administered in arm left, administration date 22Jan2022 (Batch/Lot number: unknown) at the age of 39 years as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "Rheumatoid arthritis" (ongoing), notes: States she was diagnosed with rheumatoid arthritis when she was age 24 years old.; "Autoimmune" (unspecified if ongoing), notes: she is autoimmune. Concomitant medication(s) included: HUMIRA taken for rheumatoid arthritis, start date: 21Jan2022, stop date: 21Jan2022. Vaccination history included: Bnt162b2 (Dose 1 , Lot ER8732), administration date: 01Apr2021, when the patient was 38 years old, for COVID-19 Immunization; Bnt162b2 (Dose 2, Lot EW0169), administration date: 24Apr2021, when the patient was 38 years old, for COVID-19 Immunization. The following information was reported: AXILLARY MASS (non-serious) with onset 23Jan2022, outcome "not recovered", described as "big lump under her armpit on her left arm where she got the shot and she has very much discomfort there"; BURNING SENSATION (non-serious) with onset 23Jan2022, outcome "unknown", described as "that area was just burning"; PRURITUS (non-serious) with onset 23Jan2022, outcome "unknown", described as "itching sensation"; INSOMNIA (non-serious) with onset 23Jan2022, outcome "unknown", described as "she could not sleep on it on that side"; DISCOMFORT (non-serious) with onset 23Jan2022, outcome "not recovered", described as "it was just very uncomfortable".  Additional information: Patient stated she was calling about the Pfizer vaccine booster and was not sure she called the right number but states she did get the booster dose on Saturday and she did have the side effect of a big lump under her armpit on her left arm where she got the shot and she has very much discomfort there. Patient states she was calling to see what the 2nd step was for her or what to do whether she should go to urgent care or what other step she can do. Patient was aware of reason for safety report and aware Pfizer unable to offer treatment recommendations or medical advice. Patient stated the lump started on her arm on Sunday 23Jan2022 and she did her Pfizer Covid booster shot on Saturday 22Jan2022 and knows that by Sunday night, that area was just burning and had an itching sensation and then she could not sleep on it on that side and it was just very uncomfortable. Patient stated the lump was ongoing and worse than when it began. Patient stated her 1st dose of the Pfizer Covid vaccine was administered on 01Apr2021 with lot ER8732, her 2nd dose was administered on 24Apr2021 with lot EW0169 and the booster dose was administered on 22Jan2022 with the lot number of FK9729 or FK1729 and states the handwriting on the patient card was hard to read; states her patient card has no expiry dates or NDC numbers written on it. Patient stated she had her Humira shot the day before the booster and had the Humira shot on 21Jan2022 and she was autoimmune and has rheumatoid arthritis and gets that shot of Humira once per week and has no lot number to provide for it and the dosage was 40mg 0.4mL and was provided by her rheumatologist and it was administered to her stomach; stated she has been diagnosed with rheumatoid arthritis for approximately 15 years. Time the Vaccination Was Given: 2:30 or 3:00pm. Family Medical History Relevant to AE(s): None. Relevant Tests: None. Patient stated she will just head to urgent care once she was out of work and right now was going to work and will go to urgent care at that time to see if there was something they can give her to minimize the pain.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.