didn't want to scratch arm because it looked as if it could break open; still throbbing/When patient received dose it stung; skin was swelling/ lumpy; itchy/ it started blowing up again itching the heat /still itching really bad/  started blowing up again itching the heat; hot; weird soreness; red; arm felt angry; my doctor said it looked like cellulitis; they snaked around my arm to the top of my elbow; arm blew up; Skin had tiny little peelings; felt something weird; small area that felt like punched in arm and stiffness/stiffness and hotness is moving down to the elbow; felt a cold sensation crawling up arm; This spontaneous case was reported by a consumer and describes the occurrence of CELLULITIS (my doctor said it looked like cellulitis), CONDITION AGGRAVATED (they snaked around my arm to the top of my elbow), MUSCULOSKELETAL STIFFNESS (small area that felt like punched in arm and stiffness/stiffness and hotness is moving down to the elbow), SKIN EXFOLIATION (Skin had tiny little peelings), FEELING ABNORMAL (felt something weird), VACCINATION COMPLICATION (didn't want to scratch arm because it looked as if it could break open) and IRRITABILITY (arm felt angry) in a 64-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 017C21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No medical history provided. No concomitant medication information provided.  Concurrent medical conditions included Arthritis.    On 04-May-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 04-May-2021, the patient experienced FEELING COLD (felt a cold sensation crawling up arm). On 05-May-2021, the patient experienced MUSCULOSKELETAL STIFFNESS (small area that felt like punched in arm and stiffness/stiffness and hotness is moving down to the elbow) (seriousness criterion medically significant). On 14-May-2021, the patient experienced CELLULITIS (my doctor said it looked like cellulitis) (seriousness criterion medically significant), CONDITION AGGRAVATED (they snaked around my arm to the top of my elbow) (seriousness criterion medically significant), LIMB DISCOMFORT (arm blew up), SKIN EXFOLIATION (Skin had tiny little peelings) (seriousness criterion medically significant), FEELING ABNORMAL (felt something weird) (seriousness criterion medically significant), IRRITABILITY (arm felt angry) (seriousness criterion medically significant), VACCINATION SITE WARMTH (hot), MYALGIA (weird soreness) and VACCINATION SITE ERYTHEMA (red). On 15-May-2021, the patient experienced PRURITUS (itchy/ it started blowing up again itching the heat /still itching really bad/  started blowing up again itching the heat) and VACCINATION SITE SWELLING (skin was swelling/ lumpy). On 17-May-2021, the patient experienced VACCINATION SITE PAIN (still throbbing/When patient received dose it stung). On an unknown date, the patient experienced VACCINATION COMPLICATION (didn't want to scratch arm because it looked as if it could break open) (seriousness criterion medically significant). On 26-May-2021, CELLULITIS (my doctor said it looked like cellulitis), CONDITION AGGRAVATED (they snaked around my arm to the top of my elbow), LIMB DISCOMFORT (arm blew up), SKIN EXFOLIATION (Skin had tiny little peelings) and FEELING ABNORMAL (felt something weird) had resolved. At the time of the report, MUSCULOSKELETAL STIFFNESS (small area that felt like punched in arm and stiffness/stiffness and hotness is moving down to the elbow), FEELING COLD (felt a cold sensation crawling up arm), IRRITABILITY (arm felt angry), MYALGIA (weird soreness), VACCINATION SITE PAIN (still throbbing/When patient received dose it stung), VACCINATION SITE SWELLING (skin was swelling/ lumpy) and VACCINATION SITE ERYTHEMA (red) outcome was unknown and VACCINATION COMPLICATION (didn't want to scratch arm because it looked as if it could break open), PRURITUS (itchy/ it started blowing up again itching the heat /still itching really bad/  started blowing up again itching the heat) and VACCINATION SITE WARMTH (hot) had not resolved.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown Route) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown Route), the reporter did not provide any causality assessments.   Case Crosslinked to MOD21-091006.  On Thursday, May 20, 2021- Patient reports that it has been 7 days since her first dose of vaccine and her doctor has put her on antibiotics and prednisone.  On Mon, May 17, 2021, Patient is sending pictures of her arm. On Mon, May 17, 2021, 11:45 AM- Patient reported she was still itching really bad even after taking allegra. The only thing that would stop the itching was mentholatum.  Crosslinked MOD21-091028 and MOD21-091029 Patient received first dose on 4 May 2021 at 2;30p at a drug store with lot #017C21A  in left arm(non-dominant). The over 9 days later on Friday night, she felt a weird soreness and arm felt angry, red and hot. Patient called her doctor who saw a picture of her arm and told her to take Norco that she used for arthritis. The following day her skin felt itchy and swollen- she called her pharmacist who asked her to take Allegra. Patient also reports applying coconut oil and a vapor rub on arm to help her sleep.  Patient is scheduled to receive her second dose of the Moderna vaccine tomorrow, 01Jun2021. She had already provided her demographics and her health care and vaccine facility information with previous call. Patient had recently emailed photos of her adverse events. Patient stated she prefers to be contacted by email and not by telephone. No further information provided.  Company comment: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   Most recent FOLLOW-UP information incorporated above includes: On 17-May-2021: Additional information received on 17-May-2021 and  Pictures of events updated. On 17-May-2021: Additional information received on 17-May-2021 and  Event details and treatment information was updated. On 20-May-2021: Follow up information received on 20-may-2021 and Patient treatment details and doctor description were added. On 31-May-2021: Follow up information received on 31-May-2021 and new events were added, Case is upgraded from non-serious to serious.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.