Itching under my left arm; found  many red itchy swellings in a 4-5 inch area under my left arm.; Redness; Feeling hot; slight fever; haven't taken the second shot because of immediate reaction; popped up in completely different arm than my injection site.; got hives all on my left arm all along; This spontaneous case was reported by a consumer and describes the occurrence of PRODUCT DOSE OMISSION ISSUE (haven't taken the second shot because of immediate reaction), VACCINATION COMPLICATION (popped up in completely different arm than my injection site.), URTICARIA (got hives all on my left arm all along), PRURITUS (Itching under my left arm) and PERIPHERAL SWELLING (found  many red itchy swellings in a 4-5 inch area under my left arm.) in a 75-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 013A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Hay fever and Hives. Previously administered products included for an unreported indication: OMEPRAZOLE. Concurrent medical conditions included Niacin supplementation (Severe flushing, hives, dizziness, heart racing) since 1990, Drug allergy (novocaine Everything turned pink, light-headed, heart racing, trouble breathing) since 1980, Hyperlipidemia since 1986, Irritable bowel syndrome since 1980 and Ulcer (getting more severe after meds. Quit daily omeprazole.) since 1968. Concomitant products included FISH OIL, OMEPRAZOLE, DICYCLOMINE [DICYCLOVERINE], MONASCUS PURPUREUS (RED YEAST RICE) and COLECALCIFEROL (D3) for an unknown indication.    On 03-Mar-2021 at 10:37 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 03-Mar-2021, the patient experienced PRODUCT DOSE OMISSION ISSUE (haven't taken the second shot because of immediate reaction). 03-Mar-2021, the patient experienced VACCINATION COMPLICATION (popped up in completely different arm than my injection site.) and URTICARIA (got hives all on my left arm all along). On an unknown date, the patient experienced PRURITUS (Itching under my left arm), PERIPHERAL SWELLING (found  many red itchy swellings in a 4-5 inch area under my left arm.), ERYTHEMA (Redness), FEELING HOT (Feeling hot) and PYREXIA (slight fever). The patient was treated with HYDROCORTISONE (CORTISONE [HYDROCORTISONE]) ongoing since an unknown date for Itching, at a dose of 1 dosage form. On 03-Mar-2021, PRODUCT DOSE OMISSION ISSUE (haven't taken the second shot because of immediate reaction) had resolved. At the time of the report, VACCINATION COMPLICATION (popped up in completely different arm than my injection site.), URTICARIA (got hives all on my left arm all along) and PYREXIA (slight fever) had resolved and PRURITUS (Itching under my left arm), PERIPHERAL SWELLING (found  many red itchy swellings in a 4-5 inch area under my left arm.), ERYTHEMA (Redness) and FEELING HOT (Feeling hot) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 03-Apr-2021, Body temperature: 98.1 (normal) 98.1 Degree Fahrenheit.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   The patient used cortisone cream to ease the itching.    Most recent FOLLOW-UP information incorporated above includes: On 02-Jul-2021: Follow up received and contains No new information. On 30-Jul-2021: Follow up received and patient demographics updated, added other relevant history, added lab data. added concomitant and treatment medications, added new events and outcome of the events.