Search

Purpose of Review: Idiopathic inflammatory myopathies (IIM) are a complex family of autoimmune systemic disorders which often affect muscle and/or skin. IIM cause significant morbidity and mortality, but optimal treatment is uncertain. This review provides a practical guide for using intravenous immunoglobulin (IVIG) and subcutaneous immunoglobulin (SCIG) in the management of IIM, including dermatomyositis (DM), polymyositis (PM), immune-mediated necrotizing myositis (IMNM), and spontaneous inclusion body myositis (IBM), based on relevant recent literature and experience. We summarize pertinent considerations when using IVIG in special circumstances, including myositis-related dysphagia, interstitial lung disease (ILD), calcinosis cutis, and pregnant patients. This review also discusses IVIG safety, available formulations, and costs. Recent Findings: While IVIG has been used de facto for severe IIM for over 30 years, prior clinical trials of IVIG were notably limited. Recently, however, IVIG has proven safe and effective against IIM in several high-impact publications, including a large prospective, randomized placebo-controlled phase III study in DM. Summary: IVIG is useful against both muscular and extra-muscular manifestations in many types of IIM. It can be used as a first-line, steroid-sparring agent or as add-on to other treatments, tailored to specific clinical IIM scenarios. It is generally well-tolerated and has good safety profile, but accessibility and cost still limit its use. [ABSTRACT FROM AUTHOR]

Necrotizing myositis represents a rare, aggressive form of bacterial-induced soft tissue necrotizing infection. We present a fulminant case of a 44-year-old patient with a necrotizing soft tissue infection and a history of rheumatoid arthritis transferred to our service, Cluj-Napoca Emergency County Hospital, from a local hospital where he had been admitted two days before with chills and light-headedness after an accidental minor blunt trauma in the right thigh region. After admission to our hospital and first assessment, broad spectrum antibiotherapy was started with Meropenem, Vancomycin and Metronidazole along with surgical debridement. The evolution was fulminant with rapid development of multiple organ dysfunction syndrome, therefore he was transferred to the intensive care unit, intubated, and started the volemic resuscitation and vasopressor therapy. The blood culture was positive for group A beta-hemolytic streptococcus (GAS) and high dose Penicillin G was added to the therapeutic scheme. Despite all efforts, the patient developed disseminated intravascular coagulation syndrome and died in the next hours. The clinical picture together with the findings from the autopsy were suggestive for a streptococcal toxic shock syndrome developed as a complication of GAS induced necrotizing myositis. [ABSTRACT FROM AUTHOR]

In a young man affected by skin soft tissue infections complicated with myositis, the use of hyperbaric oxygen treatment as an adjuvant therapy to surgical debridement and antibiotic therapy could improve management and prognosis. [ABSTRACT FROM AUTHOR]

Abstract In a young man affected by skin soft tissue infections complicated with myositis, the use of hyperbaric oxygen treatment as an adjuvant therapy to surgical debridement and antibiotic therapy could improve management and prognosis.

Abstract Background Pembrolizumab is an immune-checkpoints inhibitor that enhances the immune response against cancer cells and therefore is useful for the treatment of several carcinomas. However, pembrolizumab sometimes perturbs the immune system resulting in various autoimmune neurological complications. In this situation, autoimmune myositis due to pembrolizumab is a rare but not-negligible complication. Here, we report two cases of autoimmune myositis due to pembrolizumab, with systemic myositis involving levator palpebrae superioris, extraocular and hindneck muscles. Case presentation Case 1 was a 78-year-old man with advanced urinary cancer referred to the neurological ward presenting with bilateral ptosis, restriction of eye movements, dropped head and weakness in the lower extremities after pembrolizumab administration. His blood examination showed elevated serum levels of creatine kinase with positive anti-PM-Scl 75 and anti-signal recognition particle antibodies. Needle electromyography and MRI suggested systemic inflammatory myopathy. There were no findings to indicate myocardial involvement on electrocardiogram or echocardiogram. Administration of intravenous methylprednisolone following plasma exchange ameliorated creatine kinase levels and inhibited the progression of clinical symptoms. Case 2 was a 72-year-old female with lung cancer and multiple metastasis, including lymph nodes and brain. She presented with back pain, right-sided ptosis, weakness of her neck extensors and flexors and elevated serum creatine kinase after receiving pembrolizumab. Although myositis specific autoantibodies were negative, needle electromyography and MRI suggested systemic inflammatory myopathy and muscle biopsy indicated necrotizing myopathy. There were no signs indicating heart dysfunction and her electrocardiogram was normal. Clinical symptoms and serum creatine kinase levels were ameliorated after the administration of intravenous methylprednisolone. Conclusions Both cases showed atypical extensive inflammatory myositis including levator palpebrae superioris, extraocular and hindneck muscles, resembling myasthenia gravis (MG), but they did not have MG-related antibodies. Edrophonium test was negative and showed no daily fluctuation. Two previously reported cases also presented with systemic necrotizing systemic myositis involving extraocular and facial muscles caused by pembrolizumab. Idiopathic inflammatory myositis evolving levator palpebrae superioris and ocular muscles is quite rare; however, myositis due to immune-checkpoint inhibitors may preferentially involve these muscles. This case report will alert physicians to the possibility of systemic inflammatory myopathy evolving levator palpebrae superioris, extraocular and hindneck muscles mimicking MG due to pembrolizumab.

One of the most commonly prescribed lipid lowering medications are statins. In most cases, statins are well tolerated. In rare instances, statin induced necrotizing autoimmune myositis (SINAM) can occur. The following case presents a patient with a 15 year history of simvastatin use who developed SINAM following a motor vehicle accident.

Purpose: to describe an unusual case of necrotizing myositis in a rectus muscle, possibly related to BRAF inhibitor therapy. Observations: An 18-year old man with neurodegenerative Langerhans cell histiocytosis (LCH), recently started on the BRAF inhibitor dabrafenib, presented with right eye pain. Magnetic resonance imaging (MRI) orbits revealed a rectus muscle mass concerning for LCH recurrence or malignancy. Dabrafenib was stopped, and incisional biopsy of the mass was performed. The mass was absent on post-operative MRI, so no further treatment was pursued. Histopathologic evaluation was initially concerning for sarcoma, but on further analysis, appeared more consistent with necrotizing myositis. The mass did not recur, nor did the patient develop other signs or symptoms concerning for myositis or malignancy over a 24-month follow-up period. Conclusions: Necrotizing myositis has not been previously described in a rectus muscle or with BRAF inhibitor use, though myalgias and malignancies are established side effects. Necrotizing myositis may masquerade as sarcoma and should be on the differential diagnosis for a new mass in the setting of dabrafenib therapy.

Statins are commonly used lipid lowering agents which play a pivotal role in reducing cardiovascular morbidity and mortality. Often well tolerated, these HMG-CoA reductase (HMGCR) inhibitors can sometimes cause severe muscle weakness and elevated creatinine kinase (CK) often labeled as statin intolerance or statin induced myopathy. These symptoms improve after discontinuation of the offending drug along with normalization of the enzyme levels. However, an entity called Immune Mediated Necrotizing Myopathy (IMNM), a type of autoimmune mediated myopathy, has been recognized and characterized in patients with history of statin exposure where there is persistence of proximal muscle weakness, CK elevation and myofiber necrosis can be seen on muscle biopsy even after stopping statins. With the increased use of statins, there seems to be a higher incidence of IMNM cases in recent years. Here we discuss a case of anti-HMG-CoA myopathy, one of the three recognized types of IMNM that has been more commonly associated with statin exposure and highly responsive to immunotherapy.

Background: Necrotizing myositis (NM) is a life‐threatening emergency. It causes focal muscle necrosis without abscess formation or extensive involvement of the overlying fascia and soft tissue. It is a clinical diagnosis requiring a high index of clinical suspicion. Usual presentation can readily be mistaken to represent more benign pathologies such as muscular injury, viral myopathy or deep venous thrombosis. The clinical course following initial misdiagnosis is rapid deterioration into profound sepsis and progressive multiorgan failure. Prompt treatment is associated with favourable outcomes, but early diagnosis is challenging due to initial absence of cutaneous signs and symptoms. Delayed referral to surgeons with appropriate expertise results in higher morbidity and mortality. The cornerstones to treatment are complete surgical debridement, intensive care management and accurate antimicrobial therapy. Methods: We report four cases of NM demonstrating classical scenarios of initial misdiagnosis, delays in referral and review by an experienced surgeon. A review of the current literature to aid with overall management is also included. Results: Review of literature that revealed the most common presentation was antecedent prodromal flu‐like symptoms followed by rapidly progressing focal muscle pain. Patients were initially misdiagnosed followed by rapid deterioration into profound sepsis before surgical opinion was obtained. Conclusion: NM is a rare and potentially fatal disease that must be considered in the differential diagnoses of the young, healthy patient with acute limb pain and fever. A high index of suspicion will facilitate earlier management and reduce morbidity and mortality. [ABSTRACT FROM AUTHOR]

Abstract Background Necrotizing myositis is a rare but life-threatening soft-tissue infection characterized by rapidly spreading inflammation and subsequent necrosis of the affected tissue. The myositis is often caused by toxin-producing, virulent bacteria such as group A β-hemolytic streptococcus and associated with severe systemic toxicity. It is rapidly fatal unless diagnosed promptly and treated aggressively. However, necrotizing myositis is often initially misdiagnosed as a more benign soft-tissue infection as such fulminant, invasive muscle infections are rare with no more than 30 cases reported over the last century. Case presentation We illustrate the case of a 74-year-old male Caucasian initially presenting with a progressing swelling and gradually oncoming pain of the upper right extremity. Rapidly, livid discolorations of the skin, blisters, hypoesthesia and severe pain resistant to analgesics treatment developed accompanied by disruption of the arterial blood flow. Due to a manifest compartment syndrome the patient was admitted to theater for fasciotomy of the arm. After multiple revision surgeries wound closure was achieved using a pedicled, fasciocutaneous parascapular flap and a free, ipsilateral anterolateral thigh flap. Microbiological analysis revealed group A β-hemolytic streptococcus, histology a bacterial interstitial myositis with necrotic muscular fibers. Conclusions A high degree of clinical suspicion is necessary to avert potentially disastrous consequences of necrotizing myositis. Timely diagnosis, broad-spectrum antibiotic therapy, and aggressive surgical debridement of affected tissue are keys to the treatment of this serious, often life-threatening infection.

Herein, we report an elderly man with lower limb weakness due to multiple peripheral neuropathies associated with rhabdomyolysis that was identified by electro-diagnosis and hip magnetic resonance imaging (MRI). He was diagnosed with acute kidney injury due to rhabdomyolysis following prolonged immobilization after alcoholic intoxication. He complained of thigh pain, hypoesthesia, and weakness in both lower extremities. The electro-diagnostic study showed near complete axonal loss of the sciatic nerve and partial axonal loss of the femoral and obturator nerve, between the gluteal region and the proximal thigh level, which was more severe on the right side than on the left. Hip MRI revealed extensive necrotizing myositis on the gluteal, psoas, and adductor muscles, and an inflammatory lesion around multiple peripheral nerves at the pelvic and proximal thigh level. The clinical course and prognosis were discussed as an example of a neurological complication arising from an inflammatory condition related to rhabdomyolysis.

Background: Necrotizing myositis is a rare but life-threatening soft-tissue infection characterized by rapidly spreading inflammation and subsequent necrosis of the affected tissue. The myositis is often caused by toxin-producing, virulent bacteria such as group A β-hemolytic streptococcus and associated with severe systemic toxicity. It is rapidly fatal unless diagnosed promptly and treated aggressively. However, necrotizing myositis is often initially misdiagnosed as a more benign soft-tissue infection as such fulminant, invasive muscle infections are rare with no more than 30 cases reported over the last century. Case presentation: We illustrate the case of a 74-year-old male Caucasian initially presenting with a progressing swelling and gradually oncoming pain of the upper right extremity. Rapidly, livid discolorations of the skin, blisters, hypoesthesia and severe pain resistant to analgesics treatment developed accompanied by disruption of the arterial blood flow. Due to a manifest compartment syndrome the patient was admitted to theater for fasciotomy of the arm. After multiple revision surgeries wound closure was achieved using a pedicled, fasciocutaneous parascapular flap and a free, ipsilateral anterolateral thigh flap. Microbiological analysis revealed group A β-hemolytic streptococcus, histology a bacterial interstitial myositis with necrotic muscular fibers. Conclusions: A high degree of clinical suspicion is necessary to avert potentially disastrous consequences of necrotizing myositis. Timely diagnosis, broad-spectrum antibiotic therapy, and aggressive surgical debridement of affected tissue are keys to the treatment of this serious, often life-threatening infection. [ABSTRACT FROM AUTHOR]

Background: Streptococcus equi subsp. zooepidemicus is a beta-hemolytic group C streptococcus mainly causing infections in domesticated animals. Here we describe the first case of zoonotic necrotizing myositis caused by this bacterium.Case Presentation: The patient was a 73-year-old, previously healthy farmer with two asymptomatic Shetland ponies in his stable. After close contact with the ponies while feeding them, he rapidly developed erythema of his left thigh and sepsis with multiple organ failure. The clinical course was severe and complicated, requiring repetitive surgical excision of necrotic muscle, treatment with vasopressors, mechanical ventilation and continuous venovenous hemofiltration, along with adjunctive hyperbaric oxygen therapy. The patient was discharged from hospital at day 30, without obvious sequelae. The streptococcal isolate was identified as Streptococcus equi by MALDI-ToF MS, and was later assigned subspecies identification as S. equi subsp. zooepidemicus. Multilocus sequence typing identified the strain as a novel sequence type (ST 364), closely related to types previously identified in horses and cattle. A focused proteomic analysis revealed that the ST 364 expressed putative virulence factors similar to that of Streptococcus pyogenes, including homologues of the M protein, streptodornases, interleukin 8-protease and proteins involved in the biosynthesis of streptolysin S.Conclusion: This case illustrates the zoonotic potential of S. equi subsp. zooepidemicus and the importance of early clinical recognition, rapid and radical surgical therapy, appropriate antibiotics and adequate supportive measures when necrotizing soft tissue infection is suspected. The expression of Streptococcus pyogenes-like putative virulence determinants in ST 364 might partially explain the fulminant clinical picture. [ABSTRACT FROM AUTHOR]

Statins are commonly used lipid lowering agents which play a pivotal role in reducing cardiovascular morbidity and mortality. Often well tolerated, these HMG-CoA reductase (HMGCR) inhibitors can sometimes cause severe muscle weakness and elevated creatinine kinase (CK) often labeled as statin intolerance or statin induced myopathy. These symptoms improve after discontinuation of the offending drug along with normalization of the enzyme levels. However, an entity called Immune Mediated Necrotizing Myopathy (IMNM), a type of autoimmune mediated myopathy, has been recognized and characterized in patients with history of statin exposure where there is persistence of proximal muscle weakness, CK elevation and myofiber necrosis can be seen on muscle biopsy even after stopping statins. With the increased use of statins, there seems to be a higher incidence of IMNM cases in recent years. Here we discuss a case of anti-HMG-CoA myopathy, one of the three recognized types of IMNM that has been more commonly associated with statin exposure and highly responsive to immunotherapy. [ABSTRACT FROM AUTHOR]

Descrevem-se dois casos de miosite necrosante causada por Clostridium septicum em equinos. Os dois equinos apresentavam aumento de volume no membro pélvico direito e que se estendia para a região abdominal ventral. Ao corte, essa área era formada por edema sanguinolento e bolhas de gás. Os músculos esqueléticos da região caudal da coxa apresentavam áreas vermelho-escuras, crepitantes, com edema sanguinolento e, ao corte, as áreas mais profundas da musculatura tinham aspecto seco. As principais alterações histopatológicas observadas foram tumefação, vacuolização, necrose hialina e necrose flocular de fibras musculares esqueléticas. Entre as fibras, havia hemorragia, edema e grande quantidade de bacilos com tamanho de 3-6μm. Na coloração de Gram, os bacilos se apresentavam roxos (gram-positivos); quando impregnados pela prata (Warthin-Starry), se mostraram enegrecidos. Nos dois casos, C. septicum foi isolado, em ambiente anaeróbio, do líquido de edema das lesões musculares.Two cases of acute necrotizing myositis caused by Clostridium septicum in horses are described. Both horses presented swelling of the right pelvic limb extending to the ventral abdominal region. The cut surface of the affected area revealed blood-stained edema and gas bubbles. The skeletal muscles of the caudal region of the thigh of the affect limbs had dark red discolored areas of blood-stained edema and crepitation; the deep musculature was dry. The main histopathological findings were swelling, vacuolation and hyaline and floccular necrosis of skeletal myofibers; in between myofibers there were hemorrhage, edema and large amounts of bacilli. In both cases, C. septicum was isolated from the edema fluid of muscular lesions.

Background: Severe dysphagia may occur in the immune mediated necrotizing myopathies (IMNM). Neck swelling and severe dysphagia as the initial symptoms upon presentation has not been previously described. Case presentation: A 55-year-old male with a 4 week history of neck swelling, fatigue, dysphagia, myalgias, night sweats, and cough was admitted for an elevated CK. He underwent extensive infectious and inflammatory evaluation including neck imaging and muscle biopsy. Neck CT and MRI showed inflammation throughout his strap muscles, retropharyngeal soft tissues and deltoids. Infectious work up was negative. Deltoid muscle biopsy demonstrated evidence of IMNM. Lab tests revealed anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies confirming the diagnosis of HMGCR IMNM. Conclusions: HMGCR IMNM is a rare and incompletely understood disease process. Awareness of HMGCR IMNM could potentially lead to earlier diagnosis, treatment and improved clinical outcomes as disease progression can be rapid and severe. [ABSTRACT FROM AUTHOR]

Abstract This interactive self-study resource is designed for use with medical students in both preclinical and clinical years. The resource is presented as an interactive case study followed by a review of how to evaluate a patient with psoas abscess, how to develop a differential diagnosis, and the basics of treatment. This tutorial features both radiologic images and key points to help learners better understand the information presented. The presentation was created to make students aware of this uncommon but more and more frequent pathology. It also serves as a platform for learners to go through the diagnostic steps of differential diagnosis, tests, final diagnosis, assessment, and plan. Moreover, it provides students with basic aspects of the antibiotic therapy used depending on the specific bacteria.

Background: Enterovirus 71 (EV71) infections are associated with a high prevalence of hand, foot and mouth disease (HFMD) in children and occasionally cause lethal complications. Most infections are self-limiting. However, resulting complications, including aseptic meningitis, encephalitis, poliomyelitis-like acute flaccid paralysis, and neurological pulmonary edema or hemorrhage, are responsible for the lethal symptoms of EV71 infection, the pathogenesis of which remain to be clarified. Results: In the present study, 2-week-old Institute of Cancer Research (ICR) mice were infected with a mouse-adapted EV71 strain. These infected mice demonstrated progressive paralysis and died within 12 days post infection (d.p.i.). EV71, which mainly replicates in skeletal muscle tissues, caused severe necrotizing myositis. Lesions in the central nervous system (CNS) and other tissues were not observed. Conclusions: Necrotizing myositis of respiratory-related muscles caused severe restrictive hypoventilation and subsequent hypoxia, which could explain the fatality of EV71-infected mice. This finding suggests that, in addition to CNS injury, necrotic myositis may also be responsible for the paralysis and death observed in EV71-infected mice. [ABSTRACT FROM AUTHOR]

M. C. Dalakas (2011) Neuropathology and Applied Neurobiology 226-242 The review provides an update on the diagnosis of the main subtypes of inflammatory myopathies including dermatomyositis (DM), polymyositis (PM), necrotizing autoimmune myositis (NAM) and sporadic inclusion body myositis (sIBM). The fundamental aspects on muscle pathology and the unique pathomechanisms of each subset are outlined and the diagnostic dilemmas concerning the distinction of PM from sIBM and NAM are addressed. Dermatomyositis is a complement-mediated microangiopathy leading to destruction of capillaries, hypoperfusion and inflammatory cell stress on the perifascicular regions. NAM, is an increasingly recognized subacute myopathy triggered by statins, viral infections, cancer or autoimmuity with macrophages as the final effector cells causing fibre injury. In PM and sIBM cytotoxic CD8-positive T cells clonally expand in situ and invade major histocompatibility-I-expressing muscle fibres. The pathology of sporadic inclusion body myositis is complex because, in addition to the inflammatory mechanisms, there are degenerative features characterized by vacuolization and the accumulation of stressor and amyloid-related misfolded proteins. Inducible pro-inflammatory molecules, such as interleukin 1-β, may enhance the accumulation of stressor proteins. The principles for more effective treatment strategies are discussed. [ABSTRACT FROM AUTHOR]