covid arm,  its pretty big , it took all the top of their arm and is starting  to go underneath it is 6 inches wide across the top of their arm.; This got her upset; celulitis; there's no rash anywhere except the arm; After 6 days my arm still has a red swollen a size of a round grapefruit it was very itchy and hot to touch; swollen arm (size of round grapefruit/there was a little swelling; itchy/it's spreading, it started as a small egg. Also she has itching all over her head, her whole body is itching/Her head itches; hard to touch; red (injection site); This spontaneous case was reported by a nurse and describes the occurrence of CELLULITIS (celulitis) in an 80-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 040C21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concomitant products included RIVAROXABAN (XARELTO) for Eye discomfort, METOPROLOL, APIXABAN (ELIQUIS), AMBROXOL, ASCORBIC ACID (VITAMIN C CITRUS), COLECALCIFEROL (VITAMIN D [COLECALCIFEROL]), VITAMIN D3, VITAMIN B COMPLEX and CETIRIZINE HYDROCHLORIDE (ALERID) for an unknown indication.    On 27-Sep-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 27-Sep-2021, the patient experienced PRURITUS (itchy/it's spreading, it started as a small egg. Also she has itching all over her head, her whole body is itching/Her head itches), VACCINATION SITE INDURATION (hard to touch), VACCINATION SITE ERYTHEMA (red (injection site)) and VACCINATION SITE SWELLING (swollen arm (size of round grapefruit/there was a little swelling). On 02-Oct-2021, the patient experienced VACCINATION SITE WARMTH (After 6 days my arm still has a red swollen a size of a round grapefruit it was very itchy and hot to touch). On an unknown date, the patient experienced CELLULITIS (celulitis) (seriousness criterion medically significant), VACCINATION COMPLICATION (covid arm,  its pretty big , it took all the top of their arm and is starting  to go underneath it is 6 inches wide across the top of their arm.), DEPRESSED MOOD (This got her upset) and VACCINATION SITE RASH (there's no rash anywhere except the arm). The patient was treated with CEPHALEXIN [CEFALEXIN] for Adverse event, at a dose of 500 milligram. At the time of the report, CELLULITIS (celulitis), PRURITUS (itchy/it's spreading, it started as a small egg. Also she has itching all over her head, her whole body is itching/Her head itches), VACCINATION SITE WARMTH (After 6 days my arm still has a red swollen a size of a round grapefruit it was very itchy and hot to touch), VACCINATION COMPLICATION (covid arm,  its pretty big , it took all the top of their arm and is starting  to go underneath it is 6 inches wide across the top of their arm.), DEPRESSED MOOD (This got her upset), VACCINATION SITE INDURATION (hard to touch), VACCINATION SITE ERYTHEMA (red (injection site)), VACCINATION SITE RASH (there's no rash anywhere except the arm) and VACCINATION SITE SWELLING (swollen arm (size of round grapefruit/there was a little swelling) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 26-Sep-2021, SARS-CoV-2 antibody test: positive (Positive) Positive.     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.   Concomitant medications also include Alcost.  Company comment - This case concerns a 80-year-old, female patient with no relevant medical history, who experienced, serious unlisted event of cellulitis, among other non-serious events. The event occurred on an unspecified duration after first dose of Moderna COVID-19 Vaccine.  The rechallenge was unknown as the date for first dose was provided.  The benefit-risk relationship of Moderna COVID-19 Vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 02-Oct-2021: Significant followup appended, case become serious On 04-Oct-2021: Non-significant follow up added.; Sender's Comments: This case concerns a 80-year-old, female patient with no relevant medical history, who experienced, serious unlisted event of cellulitis, among other non-serious events. The event occurred on an unspecified duration after first dose of Moderna COVID-19 Vaccine.  The rechallenge was unknown as the date for first dose was provided.  The benefit-risk relationship of Moderna COVID-19 Vaccine is not affected by this report.