Erosive arthritis; Seronegative RA; This literature-non-study case was reported in a literature article and describes the occurrence of ARTHRITIS (Erosive arthritis) and RHEUMATOID ARTHRITIS (Seronegative RA) in an 81-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis.   LITERATURE REFERENCE.    The patient's past medical history included GERD. Concurrent medical conditions included Osteopenia and Thrombophilia. Concomitant products included WARFARIN for Thrombophilia.   In February 2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In March 2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In 2021, the patient experienced ARTHRITIS (Erosive arthritis) (seriousness criterion medically significant) and RHEUMATOID ARTHRITIS (Seronegative RA) (seriousness criterion medically significant). The patient was treated with METHOTREXATE in 2021 for Erosive arthritis, at a dose of Four tablets; METHOTREXATE in 2021 for Erosive arthritis, at a dose of Six tablets, tolerated well and PREDNISONE from 2021 to 2021 at a dose of Taper. At the time of the report, ARTHRITIS (Erosive arthritis) and RHEUMATOID ARTHRITIS (Seronegative RA) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Anti-cyclic citrullinated peptide antibody: Negative. In 2021, Antibody test: (Negative) anti chromatin antibody. In 2021, Antinuclear antibody (Unknown-less than 1:80): (Positive) ANA antibody was positive,1:160 titer, speckled pattern, (Negative) Anti centromere B Ab, (Negative) Anti RNP Ab, (Negative) Anti SCL70 Ab, (Negative) Anti-smith antibody, (Negative) Anti-SSA Ab and (Negative) Anti-SSB Ab. In 2021, Antiribosomal P antibody: Negative. In 2021, Autoantibody test: (Negative) Anti JO 1 Ab. In 2021, Biopsy artery: Temporal artery biopsy did not show any acute or chronic inflammatory change.. In 2021, Blood uric acid (2.7-7.4 mg/dl): 2.2 mg/dl. In 2021, C-reactive protein (Unknown-less than or equal to 1.0 mg/dl): less than 0.5 mg/dl after steroid taper and 4.8 mg/dl Initially. In 2021, Complement factor C3 (65-180 mg/dl): 106 mg/dl. In 2021, Complement factor C4 (13-52 mg/dl): 26 mg/dl. In 2021, Computerised tomogram head: did not show significant findings besides chronic microvascular changes and a left mastoid effusion. In 2021, Double stranded DNA antibody: (Negative) Anti-dsDNA Ab. In 2021, Full blood count: Within normal limits. In 2021, HLA-B*27 assay: Negative. In 2021, Magnetic resonance imaging: MRI of the right wrist showed radiocarpal/intercarpal and distal radioulnar joint synovitis, with scattered intercarpal erosions. There were also findings suggestive of extensor carpi ulnaris and flexor carpi radialis tenosynovitis. In 2021, Magnetic resonance imaging head: did not show any significant findings. In 2021, Physical examination: Focused Musculoskeletal examination showed bilateral shoulders were tender to palpitation, with reduced active and passive range of motion. Elbows were non-tender with a normal range of motion.. In 2021, Red blood cell sedimentation rate (0-30 mm/hr): 104 mm/hr, 61 mm/hr, 46 mm/hr and 33 mm/hr ESR values at one-month interval was progressively declined. In 2021, Renal function test: Within normal limits. In 2021, Rheumatoid factor: Negative. In 2021, X-ray limb: X-ray of the bilateral knee showed diffuse osteopenia with minimal degenerative changes and X-ray of wrists showed mild right and left osteoarthritis of the distal interphalangeal joint and the first carpometacarpal joints.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   No concomitant medication was provided. Patient was presented to the outpatient rheumatology clinic due to new complaints of generalized joint pains and a severe headache after receiving the second dose of the Moderna vaccination in Mar-2021. and three weeks later, she developed a headache accompanied by multiple joint pain; the joint pain was more pronounced in September of 2021. Her headache was severe, localized to the left temporal area, and not associated with vision changes or jaw claudication. She was referred to a neurologist who started her on a prednisone taper, which she continued for four weeks with minimal improvement in symptoms. Given her history of osteopenia, prednisone was discontinued, and was referred to rheumatology and patient complained of diffuse joint pain. The pain was most pronounced in the right hand, specifically her right third finger, which was also associated with diffuse swelling. The pain was severe to the point of it being debilitating. She denied similar symptoms previously.  She did not have any history of autoimmune disorders, inflammatory eye disease, inflammatory bowel disease symptoms, or other rheumatological conditions. She also did not have a history of psoriasis, pseudo-gout, and gout. She did not have any rashes or hair loss but did endorse occasional oral ulcerations.  She had synovitis of the right wrist, second-fourth metacarpophalangeal joint, and right third proximal interphalangeal joint, along with diffuse swelling on the dorsum of the right hand, which was suggestive of tenosynovitis. Her hips were non-tender with a full range of motion bilaterally and mild sacroiliac joint tenderness. Her knees and ankles were also tender bilaterally, with a painful range of motion; however, there was no effusion.  No fluids were analyzed from an affected joint. She was diagnosed with erosive arthritis and seronegative RA. A follow-up visit showed improvement in symptoms with residual swelling in the right wrist.   Most recent FOLLOW-UP information incorporated above includes: On 16-Nov-2022: Live Followup received on 16-Nov-2022 contains Mail and full text article includes significant information as medical history, treatment drug, added event, suspect product details and an updated narrative. CC: This is a literature non-study case concerning an 81-year-old female patient with past medical history of osteopenia, thrombophilia on warfarin, GERD and occasional oral ulcerations, no history of autoimmune disorders, inflammatory diseases or other rheumatological conditions and no history of psoriasis, pseudo-gout and gout, who experienced the unexpected, serious (medically significant) adverse event of special interest of Arthritis (Erosive arthritis) and Rheumatoid arthritis (Seronegative RA). Approximately 3 weeks after receiving the second dose of mRNA-1273 vaccine, the patient experienced new complaints of generalized joint pains and severe headache which was localized to the left temporal area and not associated with vision changes or jaw claudication. A non-contrast computed tomography head followed by a head magnetic resonance imaging did not show any significant findings. Temporal artery biopsy was performed but did not show any acute or chronic inflammatory changes. Laboratory assessments showed an elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The patient was referred to a neurologist who started on prednisone taper but with minimal improvement in symptoms after 4 weeks. Prednisone was discontinued given the history of osteopenia and was referred to rheumatology. At the time of the referral, the patient has diffused joint pain which was most pronounced in the right hand, specifically her right third finger, which was also associated with diffuse swelling. The pain was severe to the point of it being debilitating. On a focused musculoskeletal examination, bilateral shoulders were tender to palpitation, with reduced active and passive range of motion. Elbows were non-tender with a normal range of motion. The patient had synovitis of the right wrist, second-fourth metacarpophalangeal joint and right third proximal interphalangeal joint, along with diffuse swelling on the dorsum of the right hand, which was suggestive of tenosynovitis. Her hips were non-tender with a full range of motion bilaterally and mild sacroiliac joint tenderness. Her knees and ankles were also tender bilaterally with a painful range of motion however, there was no effusion. Complete blood count and renal functions were within normal limits. No fluids were analyzed from an affected joint. Imaging was done first with a three-view x-ray of her wrists, which showed mild right and left osteoarthritis of the distal interphalangeal joint and the first carpometacarpal joints. X-ray of the bilateral knees showed diffuse osteopenia with minimal degenerative changes. An MRI of the right wrist without contrast showed radiocarpal/intercarpal and distal radioulnar joint synovitis, with scattered intercarpal erosions. There were also findings suggestive of extensor carpi ulnaris and flexor carpi radialis tenosynovitis. The patient was diagnosed with erosive arthritis and seronegative RA and was started on Methotrexate. A follow-up visit showed improvement in symptoms with residual swelling in the right wrist. ESR values at one-month interval progressively declined. Past medical history of osteopenia remains a risk factor for the events. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This is a literature non-study case concerning an 81-year-old female patient with past medical history of osteopenia, thrombophilia on warfarin, GERD and occasional oral ulcerations, no history of autoimmune disorders, inflammatory diseases or other rheumatological conditions and no history of psoriasis, pseudo-gout and gout, who experienced the unexpected, serious (medically significant) adverse event of special interest of Arthritis (Erosive arthritis) and Rheumatoid arthritis (Seronegative RA). Approximately 3 weeks after receiving the second dose of mRNA-1273 vaccine, the patient experienced new complaints of generalized joint pains and severe headache which was localized to the left temporal area and not associated with vision changes or jaw claudication. A non-contrast computed tomography head followed by a head magnetic resonance imaging did not show any significant findings. Temporal artery biopsy was performed but did not show any acute or chronic inflammatory changes. Laboratory assessments showed an elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The patient was referred to a neurologist who started on prednisone taper but with minimal improvement in symptoms after 4 weeks. Prednisone was discontinued given the history of osteopenia and was referred to rheumatology. At the time of the referral, the patient has diffused joint pain which was most pronounced in the right hand, specifically her right third finger, which was also associated with diffuse swelling. The pain was severe to the point of it being debilitating. On a focused musculoskeletal examination, bilateral shoulders were tender to palpitation, with reduced active and passive range of motion. Elbows were non-tender with a normal range of motion. The patient had synovitis of the right wrist, second-fourth metacarpophalangeal joint and right third proximal interphalangeal joint, along with diffuse swelling on the dorsum of the right hand, which was suggestive of tenosynovitis. Her hips were non-tender with a full range of motion bilaterally and mild sacroiliac joint tenderness. Her knees and ankles were also tender bilaterally with a painful range of motion however, there was no effusion. Complete blood count and renal functions were within normal limits. No fluids were analyzed from an affected joint. Imaging was done first with a three-view x-ray of her wrists, which showed mild right and left osteoarthritis of the distal interphalangeal joint and the first carpometacarpal joints. X-ray of the bilateral knees showed diffuse osteopenia with minimal degenerative changes. An MRI of the right wrist without contrast showed radiocarpal/intercarpal and distal radioulnar joint synovitis, with scattered intercarpal erosions. There were also findings suggestive of extensor carpi ulnaris and flexor carpi radialis tenosynovitis. The patient was diagnosed with erosive arthritis and seronegative RA and was started on Methotrexate. A follow-up visit showed improvement in symptoms with residual swelling in the right wrist. ESR values at one-month interval progressively declined. Past medical history of osteopenia remains a risk factor for the events. The benefit-risk relationship of mRNA-1273 is not affected by this report.