Had a rash and pain in both arms/rash pretty big on his left arm where he got the injection/weird sympathetic arm pain and rash on the other arm in the same place; Had a rash and pain in both arms/weird sympathetic arm pain and rash on the other arm in the same place; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 73 year-old male patient received bnt162b2 (BNT162B2), administered in arm left, administration date 26Jan2021 (Lot number: EI9262) at the age of 73 years as dose 2, single and administered in arm left, administration date 05Jan2021 (Lot number: EH9899) as dose 1, single for covid-19 immunisation. Relevant medical history included: "Connective tissue disease" (ongoing), notes: was under control with medication but after he got the booster shot his disease went crazy. Family history included: "Auto immune problems" (unspecified if ongoing), notes: His mom had a lot of auto immune problems. Concomitant medication(s) included: COLCHICINE taken for connective tissue disorder. The following information was reported: RASH (non-serious) with onset Jan2021, outcome "recovered" (Jan2021), described as "Had a rash and pain in both arms/rash pretty big on his left arm where he got the injection/weird sympathetic arm pain and rash on the other arm in the same place"; PAIN IN EXTREMITY (non-serious) with onset Jan2021, outcome "recovered" (2021), described as "Had a rash and pain in both arms/weird sympathetic arm pain and rash on the other arm in the same place".  Additional information: He had very few side effects from the first and second dose of the Pfizer COVID vaccine. His first COVID shot, he had just arm pain and a rash pretty big on his left arm where he got the injection. He also had some weird sympathetic arm pain and rash on the other arm in the same place. It was weird because since he heard other friends say the same things. No other information about his friends provided. His Second shot, the side effects were much less, but he still had a little pain for a couple of days and a little rash in his left arm. Then, he went back in Aug2021 and got his COVID booster. He has an autoimmune problem with a Connective tissue disease. The connective tissue disease doesn't have a name. It is part of a family disease like scleroderma or something. His mom had a lot of auto immune problems. He feels like he got it from her. It has been under control since the doctor put him on Colchicine, 0.6mg one tablet per day. That product has not only stopped tissue from growing but reversed it. Caller didn't have NDC/lot/expiration. Everything has been fine, until he took the booster and things went haywire. The booster raised his immunity again. Somehow the booster set off his connective tissue disease, and now it is out of control. The patient has since turned 74 years old. Caller did not have a prescribing doctor. His first two vaccines were through a withheld through vaccination place. The patient did not receive any vaccination prior Covid-19 Vaccinations (within 4 weeks) and did not receive any other vaccinations within four weeks prior to the first administration date of the suspect vaccine. Other relevant medical history including but not limited to these conditions: diagnosed allergies, compromised immune status, respiratory illness, genetic/chromosomal abnormalities, endocrine abnormalities (including diabetes) and obesity Illness/AE: none. Pertinent Details: Include surgical procedures and dates: none. Family Medical History Relevant to AE(s): none. Relevant Tests: None. The patient did not have other relevant diagnostic and confirmatory test results for event(s), for example, from blood tests, cerebro-spinal fluid culture, pleural fluid culture, urine culture, diagnostic imaging, (e.g., chest X-ray, MRI).  Question: Caller stated that he has had a rash and pain in both arms after each of the three doses that he has received of the Pfizer Biontech COVID-19 vaccine. He stated that he has a female friend who has had the same "sympathetic" pain and rash in both arms. Asks if the sympathetic pain is a frequent or rare effect.   Response: Responded per the product information. Section Adverse Reactions. Also according to the appropiate VR: A review of the Prescribing Information for Pfizer Biontech Covid-19 vaccine did not find information regarding sympathetic pain. Referred to HCP.  Question: Caller asks if we have any information regarding autoimmune disorders and the Pfizer Biontech COVID-19 vaccine.  Response: Responded per the attached VR. Referred to HCP.  No follow-up attempts are possible. No further information is expected.