Right arm was very painful; Right arm was very hard/right arm was stiff; Red arm; very hard large lump; hard lump; Arm soreness; Right arm was very red/arm redness; Fever of 101.3°F for over 14 hours/fever of 100°F  persisted for 2 days; Chills; Tiredness; This spontaneous case was reported by a consumer and describes the occurrence of PAIN IN EXTREMITY (Right arm was very painful), MUSCULOSKELETAL STIFFNESS (Right arm was very hard/right arm was stiff), ERYTHEMA (Red arm ), SKIN MASS (very hard large lump) and SKIN INDURATION (hard lump) in a 74-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 021B21A, 003A21A and 012M20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Rheumatoid arthritis since 2015, Drug allergy (Lisinopril), Drug allergy (Albuterol), Parkinsonism since 2019, COPD since 2021, Blood pressure high since 2007 and High cholesterol since 2007. Concomitant products included TIOTROPIUM for COPD, METHOTREXATE and HYDROXYCHLOROQUINE SULFATE for RA, LOSARTAN, ALLOPURINOL (ALOPURINOL), LEVALBUTEROL HCL, TAMSULOSIN, SIMVASTATIN, FOLIC ACID, FISH OIL, CYANOCOBALAMIN (B12 VITAMIN STAR), ACETYLSALICYLIC ACID (ASPIRIN 81), COLECALCIFEROL (VITAMIN D3) and ACETAMINOPHEN for an unknown indication.   On 03-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 03-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 02-Sep-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 02-Sep-2021, the patient experienced PAIN IN EXTREMITY (Right arm was very painful), MUSCULOSKELETAL STIFFNESS (Right arm was very hard/right arm was stiff) and VACCINATION SITE ERYTHEMA (Right arm was very red/arm redness). 02-Sep-2021, the patient experienced ERYTHEMA (Red arm ), SKIN MASS (very hard large lump), SKIN INDURATION (hard lump) and FATIGUE (Tiredness). 02-Sep-2021, the patient experienced MYALGIA (Arm soreness). 02-Sep-2021, the patient experienced PYREXIA (Fever of 101.3°F for over 14 hours/fever of 100°F  persisted for 2 days) and CHILLS (Chills). On 03-Sep-2021, CHILLS (Chills) and FATIGUE (Tiredness) had resolved. On 06-Sep-2021, SKIN MASS (very hard large lump), SKIN INDURATION (hard lump) and PYREXIA (Fever of 101.3°F for over 14 hours/fever of 100°F  persisted for 2 days) had resolved. On 07-Sep-2021, PAIN IN EXTREMITY (Right arm was very painful), MUSCULOSKELETAL STIFFNESS (Right arm was very hard/right arm was stiff), ERYTHEMA (Red arm ), MYALGIA (Arm soreness) and VACCINATION SITE ERYTHEMA (Right arm was very red/arm redness) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 02-Sep-2021, Body temperature: 101.3°f (High) Patient had fever of 101.3°F for over 14 hours, that later came down to 100°F and persisted for 2 days..         Concomitant medication included areds vitamin for eyes.  Treatment information was not provided.   Most recent FOLLOW-UP information incorporated above includes: On 08-Sep-2021: Follow up received contains Significant information includes-history added, conmeds dose updated, Events outcome updated.; Sender's Comments: This case concerns a  74 year old male patient with relevant medical history of rheumatoid arthritis, who experienced the expected events of fatigue, myalgia, chills, vaccination site erythema and pyrexia. The patient also experienced unexpected events of pain in extremity, musculoskeletal stiffness, erythema, skin mass, skin induration. The events occurred on the same day after the third dose of the Moderna COVID-19 vaccine. The events are considered related to the product. The events are consistent with the current understanding of the mechanism of action of the vaccine. The benefit-risk relationship of the Moderna COVID-19 vaccine is not affected by this report.