patient had a rash all over her trunk, legs, buttocks, and back; red, raised, itcpatient experienced hy, burning "dots" on her thighs, back, buttocks, abdomen, trunk, and face.; patient experienced red, raised, itchy, burning "dots" on her thighs, back, buttocks, abdomen, trunk, and face.; This is a spontaneous report based on the information received by Pfizer from (manufacturer report number 2021CAT00031). A contactable consumer reported that a 69-year-old female patient received bnt162b2 (BNT162B2, solution for injection), dose unknown via an unspecified route of administration on 10Mar2021 (Batch/Lot number was not reported) as dose number, unknown single for covid-19 immunisation; amifampridine phosphate (FIRDAPSE), oral from Jan2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to Jan2021, at 5 mg, 3x/day, oral from Jan2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to Jan2021, at 20 mg, daily, oral from Jan2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to Jan2021, at 15 mg, 1x/day, oral from Jan2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to Jan2021, at 10 mg, 2x/day, oral from 2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to 2021, at 15 mg, 2x/day, oral from 2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to Feb2021, at 10 mg, 1x/day, oral from Feb2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to 22Feb2021, at 15 mg, 3x/day, oral from 23Feb2021 (Batch/Lot Number: 3185427; Expiration Date: 28Feb2021) to 2021, at 20 mg, 3x/day, oral from 2021 (Batch/Lot Number: 3185425; Expiration Date: 28Feb2021) and ongoing, at 20 mg, 3x/day for myasthenic syndrome. Medical history included diverticulitis from Sep2020, endoscopy from Sep2020 All Clear, colonoscopy from Sep2020 All Clear, hospitalisation from 11Jan2021 to an unknown date, Having muscle weakness prior to hospitalization and couldn't swallow but was  related to LEMS, Ongoing myasthenic syndrome, muscular weakness, dysphagia, constipation, gastrooesophageal reflux disease, abdominal pain upper, Hypertension, Meniere's disease, Blood cholesterol increased, ongoing dry mouth, Anxiety, Depression. Concomitant medication included pantoprazole sodium sesquihydrate (PROTONIX [PANTOPRAZOLE SODIUM SESQUIHYDRATE]) taken for an unspecified indication, start and stop date were not reported; docusate sodium (COLACE) taken for an unspecified indication, start and stop date were not reported; olmesartan medoxomil (BENICAR) taken for an unspecified indication, start and stop date were not reported; lansoprazole (LANSOPRAZOLE) taken for an unspecified indication, start and stop date were not reported; fluoxetine hydrochloride (PROZAC) taken for an unspecified indication, start and stop date were not reported; senna glycosides (SENNA GLYCOSIDES) taken for an unspecified indication, start and stop date were not reported. The patient previously took iviglob-ex for drug therapy and experienced no adverse event. On 16Jan2021, the patient started treatment with FIRDAPSE 10 MG. On unspecified dates in 2021, after starting FIRDAPSE, the patient experienced headache, nausea, muscle spasms, weight loss, and hip and back pain. On 23Feb2021 (previously reported as an unspecified date in Feb2021), the patient's FIRDAPSE dose was increased to 20 mg, taken orally, 3x/day for LEMS. After increasing the dose, the patient's nausea (previously reported) became more pronounced. As of 10Mar2021, treatment with FIRDAPSE was ongoing. The statuses of the headache, muscle spasms, nausea, weight loss, and hip and back pain were not reported. No additional information was reported. On 26Mar2021, it was learned that on 10Mar2021, the patient received an unspecified COVID vaccine. On an unspecified date in Mar2021, about one week after the vaccine, the patient had a rash all over her trunk, legs, buttocks, and back. As treatment, she used Benadryl (diphenhydramine hydrochloride) at night, some nights. As of 26Mar2021, treatment with FIRDAPSE continued, and the rash all over her trunk, legs, buttocks, and back was ongoing. She had a doctor appointment scheduled for 29Mar2021. No additional information was provided. On 05Apr2021, it was learned that the COVID vaccine was manufactured by Pfizer. On 17Mar2021, the patient experienced red, raised, itchy, burning "dots" on her thighs, back, buttocks, abdomen, trunk, and face. On 29Mar2021, the patient went to her doctor who diagnosed it as a rash and didn't provide much more than that. He did not want to prescribe oral steroids due to the patient receiving the COVID vaccine. The doctor did not say whether or not he thought it was related to the vaccine. A BUN (blood urea nitrogen) and creatinine level were drawn and the results were normal. The patient treated the rash with unspecified topical steroids and cold showers. As of 05Apr2021, the rash was improved, as it was still present, but faint and it no longer burned or itched. No additional information was provided. The patient underwent lab tests and procedures which included blood creatinine: normal on 29Mar2021, blood urea: normal on 29Mar2021, electrocardiogram: no results reported on Jan2021, hepatic enzyme: elevated on Jan2021 Liver enzymes are borderline elevated, but they aren't concerned about it. Her providers not worried about results, renal function test: no results reported on Jan2021.  The action taken in response to the event for amifampridine phosphate was dose not changed.  Therapeutic measures were taken as a result of patient had a rash all over her trunk, legs, buttocks, and back (rash), red, raised, itcpatient experienced hy, burning "dots" on her thighs, back, buttocks, abdomen, trunk, and face. (rash pruritic), patient experienced red, raised, itchy, burning "dots" on her thighs, back, buttocks, abdomen, trunk, and face. (skin burning sensation). Outcome of the events was not recovered.  No follow-up attempts are needed. Information about lot/batch number cannot be requested. No further information is expected.