皮膚筋炎／多発性筋炎

A man in his 80s with chronic obstructive pulmonary disease presented with fever, arthralgia and periorbital erythema resembling a heliotrope rash, accompanied by progressive interstitial lung disease (ILD). Laboratory investigations revealed neutrophilic leucocytosis and markedly elevated C-reactive protein, ferritin and Krebs von den Lungen-6. Dermatomyositis, particularly clinically amyopathic dermatomyositis, was considered in the differential diagnosis; however, myositis-specific autoantibodies were negative and histopathological findings supported a diagnosis of adult-onset Still's disease (AOSD). Despite the high-dose corticosteroids and ciclosporin, lung disease progressed to respiratory failure. Treatment with tocilizumab led to clinical and radiological remission with normalisation of inflammatory markers.This case highlights that AOSD can present with rapidly progressive ILD and closely mimic dermatomyositis, underscoring the importance of careful differential diagnosis and timely cytokine-targeted therapy.

PURPOSE: To describe the clinical features of patients with idiopathic inflammatory myopathies (IIM) and report the prevalence of malignancy among them within a single-center cohort in southwestern Saudi Arabia. PATIENTS AND METHODS: We conducted a retrospective study at Aseer Central Hospital, reviewing records of patients diagnosed with IIM according to the ACR/EULAR 2017 classification criteria over a five-year period (January 2021-December 2025). Demographic, clinical, laboratory, and treatment data were collected and analyzed using appropriate statistical tests. RESULTS: Twenty-nine patients were included (75.9% female; mean age 41.9 years). Dermatomyositis (DM, 12/29, 41.4%) predominated, followed by polymyositis (PM, 10/29, 34.5%) and antisynthetase syndrome (ASA, 7/29, 24.1%). Skin manifestations were observed in all DM patients, with isolated involvement in one ASA patient (100% DM vs 0.0% PM vs 14.3% ASA; p < 0.001). Creatine phosphokinase (CPK) was significantly higher in PM and ASA versus DM (medians 4884 and 6334 vs 316 U/L; p = 0.005). Interstitial lung disease (ILD) was most prevalent in ASA (71.4% vs 20.0% PM vs 16.7% DM; p = 0.029). Two females with DM aged ≥40 years developed malignancy (ovarian and breast; 2/29, 6.9%). Anti-Jo1 antibodies were present in 7 of 27 tested patients (25.9%), and were significantly associated with ILD (71.4% vs 20.0%, p = 0.023). No malignancy occurred in patients with ILD or anti-Jo1 positivity. Full muscle strength recovery was achieved in 26 of 29 patients (89.7%), though 10 of 29 patients (34.5%) required escalation to intravenous immunoglobulin and/or rituximab for refractory disease. CONCLUSION: Malignancy prevalence (2/29 patients, 6.9%) aligns with recent Saudi data but is lower than that reported in East Asian and many Western reports. In this study, cancer occurred exclusively in DM patients aged ≥ 40 years, lacking ILD or anti-Jo1 antibodies, consistent with established risk patterns. These findings support a clinically guided approach to cancer screening, particularly in patients with DM.

BACKGROUND: Polymyositis-scleroderma autoantibody (Anti-PM/Scl) associated connective tissue disease is a recognized overlap syndrome classically characterized by features of polymyositis- systemic sclerosis overlap. However, presentation with a dermatomyositis (DM) phenotype accompanied with interstitial lung disease (ILD) is less commonly reported. Pregnancy and the postpartum period are recognized immunological triggers for overlap syndromes, potentially leading to autoimmune disease. Postpartum-onset inflammatory myopathy with overlap features and significant pulmonary involvement poses substantial diagnostic challenges due to its heterogeneous clinical presentation and evolving serologic profiles. CASE PRESENTATION: We present a case of a 25-year-old Palestinian woman presenting with progressive proximal muscle weakness, characteristic dermatomyositis cutaneous manifestations, notable unintentional weight loss, and systemic symptoms 4 months postpartum. Laboratory tests showed markedly elevated creatine kinase and positive antinuclear antibodies, positive anti-PM/Scl antibodies and positive anti-dsDNA antibodies, while anti-U1-RNP antibodies were negative. Imaging demonstrated hepatomegaly and splenomegaly, and pulmonary function testing showed interstitial lung disease (ILD). Muscle biopsy confirmed inflammatory myopathy without typical perifascicular atrophy. The patient showed incomplete clinical response to treatment with corticosteroids and mycophenolate mofetil; however, transitioning to rituximab resulted in substantial clinical, pulmonary, and functional improvement. CONCLUSION: This case illustrates a diagnostically challenging presentation of postpartum-onset Anti-PM/Scl-Positive dermatomyositis-systemic sclerosis overlap syndrome complicated by ILD and multisystem involvement. It underscores the diagnostic challenges associated with overlap syndrome and connective tissue disease phenotypes, and supports the potential effectiveness of rituximab in refractory overlap myositis and reversing inflammatory ILD.

OBJECTIVES: Fibromyalgia is a chronic pain syndrome that can be seen as a comorbid condition in several autoimmune diseases; however, its characteristics have not been studied in patients with idiopathic inflammatory myopathies (IIM). Through this study, we aimed to assess the prevalence of fibromyalgia, factors associated with fibromyalgia, and the relationship between fibromyalgia and health outcomes and care utilization in patients with IIM. METHODS: Data were provided by patients in FORWARD, a US-wide longitudinal registry of adults with rheumatological diseases. Patients with a diagnosis of IIM who were enrolled from physician offices and completed biannual questionnaires on their health status were included. A fibromyalgia diagnosis was defined as meeting the 2016 modified fibromyalgia criteria. We examined the prevalence of criteria-defined fibromyalgia in IIM subgroups and compared participant characteristics and health outcomes based on the presence of fibromyalgia. Logistic regression models were conducted to identify factors associated with fibromyalgia. RESULTS: Fifty-seven (34%) of 167 patients with IIM met the fibromyalgia criteria. Patients with fibromyalgia were younger, had a lower education level and total annual income, and were more likely to be prescribed opioids for pain management. Younger age, lower education level, and comorbid anxiety were independently associated with fibromyalgia. Patients with fibromyalgia had significantly lower health satisfaction, worse patient-reported outcomes, including quality of life and physical function, and higher health care utilization. CONCLUSION: Approximately one-third of patients with IIM had criteria-defined fibromyalgia. Fibromyalgia was associated with worse patient-reported outcomes, less advantaged sociodemographic factors, and higher health care utilization in patients with IIM. Keypoints • Approximately one-third of patients with IIM had criteria-defined fibromyalgia. • Younger age, lower education level, and comorbid anxiety were independently associated with a fibromyalgia diagnosis. • Fibromyalgia was associated with less advantaged sociodemographic factors, worse patient-reported outcomes, and higher health care utilization in patients with IIM.

OBJECTIVE: Idiopathic inflammatory myopathies (IIM) are a heterogenous group of conditions with substantial morbidity but population-based epidemiology is lacking. We aimed to provide a contemporary epidemiological assessment of IIM. METHODS: Population-based study using the Clinical Practice Research Datalink (CPRD) Aurum primary care database with linkage to hospital episode data. All patients (aged >2 years) from England registered between 1 March 2002 and 31 March 2021 were included. Incidence was estimated for three main IIM subtypes: dermatomyositis (DM), inclusion body myositis (IBM) and other IIM. Incidence rate ratios using Poisson models were compared across subgroups. RESULTS: We identified n=1590 DM, n=432 IBM and n=2083 other IIM incident cases. Incidence of DM was 0.79 (95% CI 0.75 to 0.83), IBM 0.50 (95% CI 0.46 to 0.55) and other IIM 1.03 (95% CI 0.99 to 1.08) per 100 000 person-years.Females had a higher incidence of DM (adjusted incidence rate ratio (aIRR) 1.84, 95% CI 1.66 to 2.04) and other IIM (aIRR 1.09, 95% CI 1.00 to 1.19), but a lower incidence of IBM (aIRR 0.73, 95% CI 0.60 to 0.89), compared with males. South Asian, black, other and unknown ethnic groups had a higher incidence of DM and other IIM compared with those of white ethnicity, particularly individuals of black ethnicity for other IIM (aIRR 2.80, 95% CI 2.32 to 3.37).Point prevalence at study end was 0.015% for DM, 0.005% for IBM and 0.016% for other IIM. CONCLUSION: There are major demographic differences in IIM incidence, notably by sex and ethnicity. Resource planning should account for these marked differences.