Myositis In Children Research Articles

Clinical Characteristics of 118 Pediatric Patients With Acute Benign Myositis Associated With Influenza A Virus Infection.

The objective of this study was to investigate the clinical and laboratory features of acute benign myositis associated with influenza A virus infection in children. A retrospective analysis was performed on the clinical data of 118 children with acute benign myositis associated with influenza A virus infection who were admitted to the Children's Hospital of Chongqing Medical University during the epidemic period of influenza A from February 2023 to May 2023. (1) Most of the 118 children were preschool- or school-age. The most common symptom was sudden lower limb pain after fever, and bilateral calf myalgia was more common. The muscle enzyme spectrum ranged from 187.21 to 32191.00 μg/L (median: 3053 μg/L). Creatine kinase isoenzymes ranged from 5.15 to 749.7 μg/L (median 41.82 μg/L). Myoglobin ranged from 102.79 to 1200 μg/L (median 674.9 μg/L). (3) Examination: electromyography, muscle color Doppler ultrasound, radiograph and cardiac color Doppler ultrasound in Benign acute childhood myositis in children were rarely positive. (4) Treatment and prognosis: besides bed rest and a reduction of physical activity, oseltamivir treatment, drugs to improve energy metabolism, fluid replacement and alkalinization of symptomatic treatment. All children had a good prognosis without sequelae. This study summarized and analyzed the clinical characteristics of acute benign myositis associated with influenza A infection in children with the aim of allowing rapid and early diagnosis of the disease and reducing unnecessary diagnostic tests and treatments. Closely monitoring myalgia and the muscle enzyme spectrum is recommended to exclude other neuromuscular and metabolic diseases.

Inclusion Body Myositis in Children: Does it Exist?

Context: Sporadic inclusion body myositis (sIBM) is a rare type of juvenile idiopathic inflammatory myopathies (JIIMs). It mainly affects skeletal muscles but can also affect the skin and other organs in the body. Sporadic inclusion body myositis prevalence in children under 18 years old is very rare. Objectives: This review provides an overview of the evidence of sIBM in children, discusses the possible clinical and pathological features, and explores the proposed pathogenesis. Methods: A literature review of over 44 articles in PubMed and other medical libraries, such as Google Scholar and Web of Science, was carried out using terms such as JIIM, IBM, Inflammatory Myopathies in Children, and Inherited IBM. Two documented reports for sIBM were found, and the rest included the disease pathogenesis, prevalence of inherited IBM, and other myopathies in children. Results: This review discussed the prevalence and incidence of JIIM, in particular sIBM in children. While IBM is typically sporadic, there have been rare cases where it is familial and inherited. Genetic susceptibility factors are believed to play a role in sIBM. Most patients with sIBM are over 50 years old and experience significant weakness in the quadriceps; however, patients with inherited IBM (h-IBM) typically present earlier in adulthood with a distinct pattern of weakness. Sporadic inclusion body myositis can be misdiagnosed as other forms of myopathies, such as juvenile dermatomyositis (JDM) or limb-girdle muscular dystrophy (LGMD), during the early stages of the disease. The exact causes of sIBM are still unknown; however, environmental factors, genetic predispositions, and immune dysregulation might contribute to the pathogenesis of the disease. Conclusions: Sporadic inclusion body myositis is a rare form of JIIMs. Its early diagnosis in children can be challenging due to the presence of other coexisting diseases. Discussions have revolved around potential environmental factors, such as viral infections, specific myositis-specific antibodies (MSAs), such as anti-Ro52, and possibly certain human leukocyte antigen (HLA) haplotypes. Given the rarity of reported cases of sIBM in children, it is important to encourage further studies to better understand the underdiagnosed instances of this condition.

Urea/Creatinine Ratio's Correlation with Creatine Kinase Normalization in Pediatric COVID-19 Patients with Myositis: Evaluating Prognostic and Predictive Value.

Coronavirus disease 2019 (COVID-19) has been chiefly linked with substantial respiratory complications. However, emerging studies have brought attention to the occurrence of severe muscle inflammation (myositis) related to COVID-19, potentially leading to multi-organ failure and increased mortality. Myositis is generally characterized by heightened serum creatine kinase (CK) levels. Acute myositis is characterized by an infiltration of viruses into calf muscle fibers, which may cause a subsequent inflammatory response leading to calf muscle pain. Symptomatic and supportive management, along with explanation and reassurance, is all that is required in managing this condition. While the association between myositis and severe outcomes has been recognized in adults, it remains less understood in the pediatric population. The current retrospective study, conducted at Policlinico San Marco University Hospital in Catania, aimed to analyze clinical and laboratory factors associated with myositis in pediatric patients with SARS-CoV-2 infection. Between January 2022 and January 2023, ten pediatric patients diagnosed with myositis and SARS-CoV-2 infection were evaluated. The study highlighted clinical manifestations such as fever, calf muscle pain, and abnormal gait. Lab results showed elevated CK levels among other findings. All patients underwent treatment, with the majority recovering without complications. A notable correlation was observed between CK levels, blood urea nitrogen (BUN), and the urea/creatinine ratio (UCR). The study also discusses potential pathophysiological mechanisms behind SARS-CoV-2's impact on skeletal muscles, emphasizing an indirect inflammatory response. Our findings underscore that while myositis in children with SARS-CoV-2 infection appears to follow a benign and self-limiting trajectory, it is crucial to monitor specific markers for early intervention and management. Further research is warranted to elucidate the underlying mechanisms and improve clinical outcomes.

Myositis : Rare Presentation of Dengue, not Uncommon in Children

Dengue myositis is a recently recognized category of idiopathic inflammatory myopathies manifested as symmetric proximal muscle weakness with severe limb pain and high serum creatine kinase (CK) levels, in dengue patient (NS1 positive or IgM positive). A total 4 cases of dengue myositis were admitted at Shaheed Suhrawardy Medical College during the period from August to October, 2023. All were male & they presented mainly with severe limp pain with inability to walk they were diagnosed as dengue fever serologically. Two cases presented during febrile phase & two following fever. Their S. CPK level were high with mildly low platelet count. None of them developed shock or hemorrhagic manifestation. They were treated supportively and all 4 cases recovered without any sequelae. Dengue myositis in children is usually benign and is differentiated from other causes of flaccid paralysis by tenderness of calf and thigh muscles and raised CPK levels with other normal neurological findings. But sometimes it may result in serious consequences, so all children with dengue infection should be followed up carefully with S.CPK level J Bangladesh Coll Phys Surg 2023; 41: 101-104

Characteristics and Outcomes of Juvenile Dermatomyositis (JDM) in Thai Children: Experience from a Tertiary Referral Center

Background: Juvenile dermatomyositis (JDM) is the most common autoimmune myositis in children. However, there is a paucity of data on the clinical characteristics of JDM patients in Thailand. Objective: To describe the clinical manifestations, investigations, treatments, complications, and outcomes of JDM in Thailand. Materials and Methods: A bidirectional descriptive study based on past medical records review. All children younger than15 years diagnosed with JDM by Bohan and Peter criteria at King Chulalongkorn Memorial Hospital between January 2010 and December 2022 were enrolled. Results: Thirteen cases were identified with 69% female. The median age at diagnosis and median time to diagnosis were 3.4 (IQR 2 to 6.5) years and 3.5 (IQR 1.2 to 8) months, respectively. The common clinical presentations at disease onset were weakness at 100%, Gottron papules at 69%, and heliotrope rash at 46%. Lactate dehydrogenase was elevated in all cases at diagnosis. Evidence of muscle inflammation was found in 78% of biopsies, 80% of EMGs, and 100% of MRIs. The most common myositis specific Ab was anti-NXP2 at 64%. Most patients had polyphasic disease courses. More than half of the patients, or 62%, developed calcinosis. Six of thirteen cases received recommended treatment with prednisolone and methotrexate at diagnosis. One patient with calcinosis had a good response with infliximab. Conclusion: The present review underscores that JDM patients with younger age at diagnosis will need to be monitored closely and need aggressive long-term treatment. Prompt treatment should be managed according to the severity of symptoms to improve clinical outcomes and prevent serious complications. Keywords: JDM; Calcinosis cutis; Myositis autoantibody; Children; Developing countries

Juvenile dermatomyositis associated with autoantibodies to small ubiquitin-like modifier activating enzyme: a report of 4 cases from North India and a review of literature.

Juvenile dermatomyositis (JDM) is the commonest inflammatory myositis in children. The clinical phenotype is often characterized by the presence of myositis-specific antibodies (MSA). Antibodies to small ubiquitin-like modifier activating enzyme (SAE) are amongst the rarest MSA reported in children. A review of medical records of all patients diagnosed to have JDM during the period January 1992-April 2022 in our institute was done. Case records of children with JDM who had significant positivity for anti-SAE antibody by myositis immunoblot were analysed in detail. Of the 140 children with JDM, MSA immunoblot was carried out in 53 patients-4 (7.5%) amongst these had significant positivity for anti-SAE antibodies. Median age of onset of symptoms was 5.5years (range: 5-11years). Clinical features at presentation included fever, photosensitivity, heliotrope rash, and Gottron papules. Clinically significant proximal muscle weakness was noted in 3/4 patients; 1 had no discernible weakness but had radiological evidence of myositis. None of the 4 patients had evidence of interstitial lung disease or calcinosis. All patients were treated with intravenous pulse methylprednisolone: subcutaneous weekly methotrexate and hydroxychloroquine. One patient received mycophenolate mofetil because of a relapse of muscle disease, while none received cyclophosphamide or biologics. Median follow-up duration was 21.5months (range: 6-39months). Anti-SAE antibodies were found in 4/53 (7.5%) of North Indian children with JDM. All 4 patients had predominant cutaneous manifestations followed by muscle disease. Response to treatment was brisk and sustained. None had developed calcinosis in the follow-up. 1. We report high prevalence of anti-SAE antibody positivity (7.5%) in North Indian cohort of JDM. 2. Cutaneous disease precedes muscle weakness in children with anti-SAE positive JDM. 3. No evidence of interstitial lung disease/calcinosis was seen in these children.

Cardiovascular Abnormalities in Juvenile Dermatomyositis: A Scoping Review for the Clinical Rheumatologists.

Juvenile dermatomyositis (JDM) is a common form of inflammatory myositis in children. Vasculopathy and endothelial dysfunction play significant roles in the pathogenesis of JDM. Cardiac involvement in JDM is often underestimated, and it may be a potential indicator of poor prognosis. Cardiac dysfunction in JDM can occur both in the acute and chronic stages of the disease. Amongst the acute complications, acute congestive heart failure (CHF), myocarditis, arrhythmia, and complete heart block are common. However, these remain unrecognized due to a lack of overt clinical manifestations. Increased rates of cardiovascular abnormalities have been noted with anti-SRP and anti-Jo 1 auto-antibody positivity. Long-term follow-up studies in JDM have shown an increased prevalence of hypertension, atherosclerosis, coronary artery disease, and metabolic syndrome in adolescence and adulthood. Monitoring of body-mass index, blood pressure, and laboratory evaluation of fasting glucose and lipid profile may help in identifying metabolic syndrome in children with JDM. Steroid-sparing agents, daily exercise, and a healthy diet may reduce such long-term cardiac morbidities. Current use of multimodality imaging such as stress-echocardiography, contrast-enhanced echocardiography, cardiac magnetic resonance imaging, and positron emission tomography has increased the diagnostic yield of subclinical heart disease during acute and chronic stages of JDM. This review elaborates on different aspects of cardiac dysfunction in JDM. It also emphasizes the importance of cardiac screening in long-term follow-up of children with JDM.

Evaluation of the prevalence and clinical and laboratory features of acute viral myositis in children with influenza referred to the emergency department of Ali Asghar Tehran Hospital in 2019 and 2020.

ABSTRACTIntroduction:Influenza-related viral myositis is observed mostly in children with influenza, and the disease is more common in influenza type B. The aim of the present study was to evaluate the prevalence, and clinical and laboratory features of acute viral myositis in children with influenza in 2019 and 2020.Methods:This retrospective cross-sectional study was performed in Ali Asghar Hospital, from December 2019 to February 2020. Children aged 2–14 years with symptoms of acute onset of fever, along with the symptoms of influenza with or without muscle pain who referred to the emergency department of Hazrat Ali Asghar Children’s Hospital, were included in the study. The data were collected and analyzed by Statistical Package for the Social Sciences (SPSS) version 22.Results:Out of the 105 participants in this study, 62 (59%) were male and the rest were female. The average age of the patients was 5.34 years (SD = 2.63). Clinical signs of lower limb pain, myalgia, lameness, weakness, and lethargy were significantly more common in patients with myositis (P-value < 0.05). In-vitro examination demonstrated that creatine phosphokinase (CPK), aspartate aminotransferase (AST), and aAlanine aminotransferease (ALT) levels were significantly higher in patients with myositis.Conclusion:Based on the present results, the clinical symptoms in patients are quite clear, and based on the symptoms, it is possible to diagnose and treat myositis without relying on laboratory findings; due to the self-limitation of this complication and lack of the need for complex treatments in case of early diagnosis, physicians can diagnose and treat many cases, depending on the clinical symptoms and the accuracy of the examination.

Value of strain-wave sonoelastography as an imaging modality in assessment of benign acute myositis in children

Although sonoelastography is applied in assessment of many organs, studies for evaluation of muscles are very few in number and are mostly limited to adults. With this prospective study, we aimed to evaluate the value of sonoelastography in assessment of influenza related benign acute myositis in children. This study enrolled 25 patients with a clinical diagnosis of benign acute childhood myositis (BACM) and 25 age and sex-matched healthy controls. All patients presented to our emergency department with the complaint of inability to walk and had increased serum creatine kinase (CK) levels. All patients underwent strain elastography of the gastrocnemius muscle, and an elastography score was assigned to each patient by using a previously published 5 point-color scoring system. The findings were compared with those of the control group. No statistically significant difference was detected regarding age, weight, height, or body mass index (BMI) between patient and control groups. A statistically significant difference was found between the final elastography scores of the patient and control groups, mean values being 4.16 ± 0.75 versus 3.08 ±0.40, respectively (p < 0.001). Sonoelastography yielded a sensitivity of 80%, positive predictive value of 87%, specificity 88%, negative predictive value of 81.5%, and an overall accuracy of 84 %. Sonoelastography proves to be a valuable tool for diagnosis of BACM. It is one of the available ultrasound techniques in a radiology department and may particularly evolve to become a useful routine ancillary technique for investigation and follow-up in these cases.

Don't Forget the Flu - Determining the Etiology of Infective Myositis in a Child: A Case Report.

IntroductionInfective myositis is an acute, self-limited condition, rarely occurring in children with recent viral infections. The condition is often overlooked by emergency physicians when endeavoring to exclude other diagnoses included in the differential. Diagnosis of the condition can be difficult when based purely on clinical presentation because it shares symptoms with much more concerning neurological illnesses. A few simple laboratory tests are indicated to reach the correct diagnosis.Case ReportThe following case report describes a three-year-old female diagnosed with a recent upper respiratory tract infection presenting to the emergency department with complaints of fatigue and inability to walk. She was diagnosed with an influenza-like illness three days prior by her pediatrician, the symptoms of which had mostly resolved by the time of presentation.ConclusionMuscle weakness and abnormal, uncoordinated gait with an acute upper respiratory tract infection in a child may be cause for concern, prompting unnecessary work-up. Emergency physicians should be aware of the signs and symptoms of influenza-associated infective myositis in children, especially during influenza season.

Juvenile Dermatomyositis and the Inflammatory Myopathies.

The inflammatory myopathies comprise disorders of immune-mediated muscle injury. The histopathology and clinical features help distinguish them. Juvenile dermatomyositis (JDM) is the most common form of myositis in children and adolescents. Children with JDM present with proximal muscle weakness and characteristic rashes. The presentation is similar in children and adults, but JDM is a primary disorder and the adult form often is concerning for a paraneoplastic syndrome. Proximal muscle weakness occurs with dermatomyositis, polymyositis, and immune-mediated necrotizing myopathy, but the latter two conditions have no dermatologic findings or distinct tissue changes which set them apart from dermatomyositis. Inclusion body myositis, also included in the inflammatory myopathies, presents with more distal involvement, and microscopically exhibits identifiable rimmed vacuoles. We review key features of these disorders, focusing in more detail on JDM because it is more often encountered by the child neurologist.

Juvenile dermatomyositis - A case report with review on oral manifestations and oral health considerations

Juvenile Dermatomyositis is the most common inflammatory myositis in children, distinguished by proximal muscle weakness, a characteristic rash and Gottron’s papules. The oral lesions most commonly manifest as diffuse stomatitis and pharyngitis with halitosis. We report a case of an 8 year old male with proximal muscle weakness of all four limbs, rash, Gottron’s papules and oral manifestations. Oral health professionals must be aware of the extraoral and intraoral findings of this rare, but potentially life threatening autoimmune disease of childhood, for early diagnosis, treatment, prevention of long-term complications and to improve the prognosis and hence, the quality of life for the patient.

Outcome of Benign Acute Childhood Myositis: The Experience of 2 Large Tertiary Care Pediatric Hospitals.

The aims of the study were to determine the evolution of benign acute childhood myositis in children and to assess the relationship between creatine phosphokinase (CPK) values and myoglobinuria. A retrospective study of patients with benign acute childhood myositis seen in 2 tertiary care university-affiliated pediatric hospitals during overlapping 4-year periods. Demographic data, historical details, clinical, and laboratory results were extracted from the charts of children younger than 16 years with a CPK greater than 3 times normal. Complications, treatments, and outcomes were recorded. Fifty-four children were included, 43 (80%) were male, and mean age was 7.3 years (median [range], 6 [3-16] years), none showed abnormal neurological findings, manifested hematuria, or developed renal failure. Mean CPK level at presentation was 1872 IU/L (range, 511-8086 IU/L). None developed renal failure, and there were no adverse outcomes on follow-up. Acute childhood myositis is a predominantly benign disease. Neurological examination is usually normal and rhabdomyolysis is rare. Although severe pathological comorbid conditions must be excluded, a complete history and examination, coupled with simple blood and urine tests, can help minimize unnecessary diagnostic investigations.

A rare case of juvenile dermatomyositis and review of literature

Idiopathic inflammatory myopathies are rare group of systemic connective tissue diseases. The hallmark of these disorders is symmetrical chronic inflammation and weakness of proximal muscles. Juvenile dermatomyositis (JDM) is the most common inflammatory myositis in children. We describe a rare case of JDM in a 4-year-old female child who presented with characteristic cutaneous rash and proximal muscle weakness.

Efficacy of ultrasound elastography in detecting active myositis in children: can it replace MRI?

Juvenile idiopathic inflammatory myopathy is a rare yet potentially debilitating condition. MRI is used both for diagnosis and to assess response to treatment. No study has evaluated the performance of US elastography in the diagnosis of this condition in children. To assess the performance of compression-strain US elastography in detecting active myositis in children with clinically confirmed juvenile idiopathic inflammatory myopathy and to compare its efficacy to MRI. Children with juvenile idiopathic inflammatory myopathy underwent non-contrast MR imaging as well as compression-strain US elastography of the quadriceps muscles. Imaging findings from both modalities were compared to each other as well as to the clinical determination of active disease based on physical examination and laboratory data. Active myositis on MR was defined as increased muscle signal on T2-weighted images. Elastography images were defined as normal or abnormal based on a previously published numerical scale of muscle elastography in normal children. Muscle echogenicity was graded as normal or abnormal based on gray-scale sonographic images. Twenty-one studies were conducted in 18 pediatric patients (15 female, 3 male; age range 3-19years). Active myositis was present on MRI in ten cases. There was a significant association between abnormal MRI and clinically active disease (P = 0.012). US elastography was abnormal in 4 of 10 cases with abnormal MRI and in 4 of 11 cases with normal MRI. There was no association between abnormal elastography and either MRI (P > 0.999) or clinically active disease (P > 0.999). Muscle echogenicity was normal in 11 patients; all 11 had normal elastography. Of the ten patients with increased muscle echogenicity, eight had abnormal elastography. There was a significant association between muscle echogenicity and US elastography (P < 0.001). The positive and negative predictive values for elastography in the determination of active myositis were 75% and 31%, respectively, with a sensitivity of 40% and specificity of 67%. Compression-strain US elastography does not accurately detect active myositis in children with juvenile idiopathic inflammatory myopathy and cannot replace MRI as the imaging standard for detecting myositis in these children. The association between abnormal US elastography and increased muscle echogenicity suggests that elastography is capable of detecting muscle derangement in patients with myositis; however further studies are required to determine the clinical significance of these findings.

All-trans retinoic acid-induced inflammatory myositis in a patient with acute promyelocytic leukemia

All-trans retinoic acid (ATRA), a component of standard therapy for acute promyelocytic leukemia (APL), is associated with potentially serious but treatable adverse effects involving numerous organ systems, including rare skeletal muscle involvement. Only a handful of cases of ATRA-induced myositis in children have been reported, and none in the radiology literature. We present such a case in a 15-year-old boy with APL, where recognition of imaging findings played a crucial role in making the diagnosis and facilitated prompt, effective treatment.

An update on inflammatory myositis in children

Childhood myositis (juvenile idiopathic inflammatory myopathies - JIIMs) is a rare, but important, group of rheumatic diseases. There has been continuing worldwide progress in the understanding of these diseases, and continuing pursuit of better therapies. We review some important contributions from the recent published literature. Environmental triggers are present in the majority of children with myositis. Cancer is almost never a cause. Newer findings implicate a host of immunologic aberrations, perhaps driven by type I interferons, in addition to the humoral immunity long associated with juvenile dermatomyositis (JDM). Myositis-specific antibodies, once thought to be rare in JIIM, are now found in a significant minority because of the characterization of new antibodies. Although mortality is low, recent studies highlight the accumulation of tissue damage that occurs in JDM. Biologic therapies have an unclear place in the treatment of JIIM, but new protocols are being studied and may lead to better outcomes. Physical exercise, once controversial, likely has a role to play in treatment. International work is continuing to expand our knowledge of the JIIM.

Juvenile Dermatomyositis in Iranian Children; a Case Series Report

Objective: Juvenile dermatomyositis (JDM) is the most common inflammatory myositis in children, distinguished by proximal muscle weakness and a characteristic rash. Inflammatory cell infiltrates result in vascular inflammation, the underlying pathology in this disorder. Extramuscular manifestations include joint contracture, dysphagia, cardiac disturbances, pulmonary symptom and subcutaneous calcifications. This study is aimed to evaluate the clinical features and outcomes of juvenile dermatomyositis (JDM) in Iranian children and compare the achieved data with the relative literature. Methods: We retrospectively studied 14 patients, whose diagnosis of juvenile dermatomyositis was made according to the Bohan and Peter\\\'s diagnostic criteria. During the last 7 years we evaluated the clinical manifestations and the outcomes of these patients. Results: Average onset age was 7 years. Muscle weakness occurred in 85%; heliotrope rash 57%; Gottron papules 35%, calcinosis 14.2%; 74.9% had at least one abnormal muscle enzyme result. Muscle biopsy performed in 31.8% was abnormal in 90.9% of cases and electromyogram was abnormal in 85.7%. All patients received corticosteroids; some patients had in addition at least one as needed: methotrexate, hydroxychloroquine, IV immunoglobulin, or cyclosporin. Mean follow up of these patients was 36 months and one case of mortality happened in follow up period. Conclusion: This study indicates that early diagnosis and aggressive treatment is highly successful in minimizing the long term sequelae of JDM, including calcinosis.

Recurrent bilateral orbital myositis: case report and review of the literature

Orbital myositis in children is uncommon. Recurrence is a major challenge in management. An 11-year-old Malay girl who presented with bilateral orbital myositis with recurrent attacks of diplopia is reported.

Clinical and laboratory characteristics of 26 cases of acute benign myositis in children

目的 探讨儿童急性良性肌炎的病因、临床及实验室检查特点.方法 分析26例患儿的临床及实验室资料.结果 26例患儿均呈急性起病,病前有呼吸道感染21例,消化道感染5例;多发生在学龄前期和学龄期儿童,男孩多见;冬春季发病高,主要表现为双下肢肌肉疼痛和步态异常,血清肌酸磷酸激酶(CPK)增高数十倍以上,CPK的下降与临床症状的消失相平行.该病具有自限性,无特殊治疗方法.结论 本病起病急,以双下肢肌肉疼痛伴步态异常为特点,CPK异常升高,预后良好。