Tip of tongue burning; Inside of lip red burning along the gum line; Inside of lip red burning along the gum line; Part of the rash is smooth and part of it has little bumps; hot on left arm around the injection site/the area is warm to the touch; left arm rash/rash at the injection site, felt like an insect bite; The area is red; Itchy; Felt rush fluttering of heart, could be nerves; Could be nerves; A spontaneous report was received from a consumer concerning a 74-year-old, male patient, who received Moderna's COVID-19 vaccine (mRNA-1273) and experienced rush fluttering of heart, could be nerves/cardiac flutter, tip of tongue burning/tongue discomfort, inside of lip red burning along the gum line/oral discomfort/gingival discomfort, left arm rash, rash at the injection site, felt like an insect bite/vaccination site rash, hot on the left arm around the injection site, the area is warm to the touch/vaccination site warmth, part of the rash is smooth and part of it has little bumps/rash papular, the area is red/vaccination site erythema, itchy/vaccination site pruritus and could be nerves/nerve injury.   The patient's medical history, was not provided by the reporter. Concomitant medications reported included clonazepam, vitamin D3, curcumin, acetyl salicylic acid, famotidine, estradiol patch, vitamins, coq 10, and propranolol.   On 19 Feb 2021,prior to the onset of the events, the patient received their first of two planned doses of mRNA-1273 (Batch number: 025J20A) intramuscularly in the left arm for prophylaxis of COVID-19 infection.   On 19 Feb 2021, 5 minutes after receiving the vaccine, while she was in the observation room, she felt a little rush and a flutter in her heart. She was not sure if that was due to her nervousness and anxiety in receiving the shot. That the feeling subsided within 15 minutes.  On 28 Feb 2021, 9 days after receiving the vaccine, she experienced a rash at the injection site. It first felt like an insect bite and started to itch. When she saw the rash, it covered a larger area. The area is warm to the touch and red. The rash is smooth and part of it has little bumps. When she runs her hand over the rash, it seems to get redder. The rash seems to be getting better than when it first started. The patient also experienced tip of tongue burning, inside of lip red burning along the gum line.  Treatment for the events included gargling warm water and salt, curcumin, and eucalyptus cream.   Action taken with mRNA-1273 in response to the events was not reported.   The outcome of the events, rush fluttering of heart, could be nerves was reported to be resolved on 28 Feb 2021. The outcome of the events tip of tongue burning, inside of lip red burning along the gum line, hot on the left arm around the injection site, the area is warm to the touch, part of the rash is smooth and part of it has little bumps, the area is red, and itchy were unknown.  The outcome of the event left arm rash, rash at the injection site, felt like an insect bite was reported to be recovering.; Reporter's Comments: 74 Y/O F had serious unexpected cardiac flutter with "nerves" and NS unexpected tongue discomfort, oral discomfort, gingival discomfort, rash popular, vaccination site warmth and expected vaccination site rash, vaccination site pruritus, vaccination site erythema. Cardiac flutter 5 minutes after first dose. Cardiac flutter resolved. Based on current available information and temporal association between use of the product and the start date of the event, a causal relationship cannot be excluded.