BRIEF REPORT High frequency of rheumatic regional pain syndromes in first-degree relatives of patients with rheumatoid arthritis Lorena Pérez-Barbosa 1 & Mario Alberto Garza-Elizondo 1 & David Vega-Morales 1 & Jorge Antonio Esquivel-Valerio 1 & Ingris Peláez-Ballestas 2 & Brenda Roxana Vázquez-Fuentes 1 & Dionicio Ángel Galarza-Delgado 1 Received: 30 September 2019 /Revised: 20 February 2020 /Accepted: 5 March 2020 # International League of Associations for Rheumatology (ILAR) 2020 Abstract First-degree relatives (FDR) of patients with rheumatoid arthritis (RA) have a higher risk for the development of RA. In the stages prior to the development of arthritis, nonspecific musculoskeletal (MSK) manifestations may occur. The aim of the study is to describe the frequency of rheumatic regional pain syndromes (RRPS) in FDR of RA patients. A cross-sectional study was carried out from July 2016 to September 2018. Parents, offspring, and siblings of RA patients completed the Community Oriented Program in the Rheumatic Diseases (COPCORD) questionnaire. Rheumatoid factor (RF) IgG, IgM, and IgA; anticitrullinated peptide antibodies (ACPAs); C-reactive protein (CRP); and erythrocyte sedimentation rate (ESR) were determined. All subjects with a positive COPCORD (defined by the presence of musculoskeletal pain) were evaluated and classified. Three hundred thirty-five FDRs participated, 75.8% were female, mean age of 44.15 years; 138 (41.2%) were diagnosed with at least one RRPS; 72 (21.5%) had rotator cuff tendinitis, 51 (15.2%) pes anserine bursitis, and 39 (11.6) lateral epicondylitis; RA was diagnosed in 24 (7.16%) subjects, undifferentiated arthritis (UA) in 30 (8.9%) and inflammatory arthralgia (AI) in 104 (31%). We found anti- CCP positivity in 6.8%, RF IgA in 22.3%, RF IgM in 48.6%, and RF IgG in 8.9%. The presence of RRPS was higher in this RA- FDR group compared to general population. Clinical evaluation of this risk group should include screening for RRPS. Key Points • The frequency of rheumatic regional pain syndromes in first-degree relatives of patients with rheumatoid arthritis was 41%. • Rotator cuff tendinitis was detected in 21.5%, higher than reported in the Mexican population. • The presence of RRPS in this risk group could be considered as one of the first manifestations of RA. Keywords Autoimmunity . Relatives . Rheumatism . Rheumatoid arthritis . Shoulder pain Introduction First-degree relatives (FDR) of patients with rheumatoid arthritis (RA) have a higher risk for the development of the disease [1]. A higher prevalence of joint symptoms compared with individuals with no family history of RA has been described [2]. In the stages prior to the development of RA, nonspecific musculoskel- etal (MSK) manifestations may occur. Rheumatic regional pain syndromes (RRPS) comprise clinical extra-articular soft tissue pathologies and nerve entrapments, with an occurrence ranging from 0.7 to 15% around the world [3]. RRPS have not been well studied in FDR nor have they been described in the stages prior to the development of RA. The aim of this study was to describe the frequency of RRPS in a selected high-risk population for RA development, using a screening tool. Materials and methods An observational, cross-sectional study nested in an inception cohort from RA first-degree relatives in a Mexican university hospital done from July 2016 to September 2018. * Mario Alberto Garza-Elizondo mariogarz@hotmail.com 1 Rheumatology Service and Internal Medicine Department at Hospital Universitario “Dr. José Eleuterio González”, Universidad Autónoma de Nuevo León, Ave. Gonzalitos 235 Norte, Colonia Mitras Centro, 64020 Monterrey, Nuevo León, Mexico 2 Rheumatology Unit, Hospital General de México “Dr. Eduardo Liceaga”, Dr. Balmis 148, Doctores, 06720 México City, Mexico Clinical Rheumatology https://doi.org/10.1007/s10067-020-05029-z