[Myositis caused by a mycoplasma infection]

Mycoplasma pneumonia infection can be associated with neurological manifestations such as meningoencephalitis, cerebellitis, aseptic meningoitis, polyradiculopathy, transverse myelitis, cranial nerve palsies and myositis [4, 5]. We report a case of a white female 11 years, 2 months old child, who presented with a 3 day history of pain in the left leg. The electromyograpy showed pathological signs. We found a serological titer of IgM antibodies for Mycoplasma pneumoniae. By treatment with erythromycin the complaints improved quickly.

CONCLUSION

A myositis can be caused with an infection with Mycoplasma pneumoniae. The differential diagnosis is essential.

A severe case of subacute sarcoid myositis

A 46-year-old woman presented progressive proximal weakness and dysphagia. Her serum creatine kinase and myoglobin levels were markedly elevated. Chest X-rays revealed bilateral swelling of the hilar lymph nodes. Needle electromyography demonstrated active denervation and early recruitment. MRI of her skeletal muscle showed focal high intensities on T1-weighted images that were associated with diffusely increased signal intensities on T2-weighted images. Muscle biopsy revealed infiltration of inflammatory cells associated with non-caseating granulomas, and there was widespread segmental fiber necrosis, where necrotic fibers appeared regardless of these granulomas. Immunohistochemical analysis of the surface markers of the infiltrating cells showed CD68- and CD4-positive cells infiltrating into the central area of the granuloma, while CD8-positive cells infiltrating into the endomysium and the periphery of the granulomas. The characteristic histology of the granuloma confirmed the diagnosis of sarcoidosis. The diffuse muscle pathology was consistent with the patient's severe clinical course.

Autoantibodies in thymoma-associated myasthenia gravis with myositis or neuromyotonia

BACKGROUND

About 50% of patients with thymoma have paraneoplastic myasthenia gravis (MG). Myositis and myocarditis or neuromyotonia (NMT) will also develop in some. Patients with thymoma-associated MG produce autoantibodies to a variety of neuromuscular antigens, particularly acetylcholine receptor (AChR), titin, skeletal muscle calcium release channel (ryanodine receptor [RyR]), and voltage-gated potassium channels (VGKC).

OBJECTIVE

To examine whether neuromuscular autoantibodies in patients with thymoma correlate with specific clinical syndromes.

METHODS

Serum and plasma samples from 19 patients with thymoma-associated MG, of whom 5 had myositis and 6 had NMT, underwent testing for antibodies to AChR, titin, RyR, and VGKC.

RESULTS

Antibodies to AChR and titin were found in 19 and 17 patients, respectively. Antibodies to RyR correlated with the presence of myositis (P = .03); they were found in all 5 patients with myositis and in only 1 patient with NMT, but also in 4 of 8 patients with neither disease. Antibodies to VGKC were found in 4 patients with NMT, 1 of 3 patients undergoing testing for myositis, and 2 of 7 patients undergoing testing with neither comorbidity. Presence of RyR antibodies correlated with high levels of titin antibodies.

CONCLUSIONS

The results appear to distinguish partially between 3 groups of patients with thymoma-associated MG: the first with RyR antibodies and myositis or myocarditis, the second with NMT without RyR antibodies, and the third without RyR antibodies, myositis, or NMT. Differences in the thymoma may underlie these pathologic associations.

Two cases of acute myositis associated with influenza A virus infection in the elderly

During the influenza epidemic of 1998-1999, we observed two elderly patients with influenza-like symptoms who had evidence of acute myositis with elevated serum enzymes. Influenza A infection was confirmed serologically in either case. The present cases suggest that it is important to distinguish influenzal myositis from other forms of myopathy in the elderly patients.

Idiopathic inflammatory muscle disease: clinical aspects

Although much remains to be learned about the immune-mediated myositis syndromes, information generated from recent studies in a number of areas may assist physicians in patient management. Topics reviewed here include: data supporting the association of myositis with cancer and the appropriate evaluations for malignancy in a myositis patient; an approach to the assessment of patients with dermatomyositis sine myositis; the usefulness of the clinicopathological and serological classifications; a discussion of whether childhood and adult myositis are the same or different entities; a review of those prognostic factors to consider in the clinical management of myositis patients; current approaches and their limitations for assessing disease activity and damage. To improve our limited understanding of the myositis syndromes, national and international collaborations are needed to obtain the necessary numbers of subjects, given the rarity and heterogeneity of these disorders.

[Myositis specific autoantibodies as a new diagnostic criterion for idiopathic inflammatory myopathies]

Myositis specific autoantibodies (MSA) are the most specific diagnostic criteria for idiopathic inflammatory myopathies (IIM). There is no evidence of MSA presence in patients with other neuromuscular or connective tissue diseases. MSA are associated with homogeneous clinical syndromes: antisynthetases with antisynthetase syndrome, anti-SRP with severe, resistant to treatment myositis, anti-Mi-2 with classic, benign dermatomyositis. Therefore it is important to include the myositis specific antibodies into routine diagnostic scheme of IIM.

All-trans-retinoic acid-induced myositis: a description of two patients

All-trans-retinoic acid (ATRA) induces complete clinical remissions in a high proportion of patients with acute promyelocytic leukemia and has become the standard induction therapy. Its use as a single agent results in short-lived remissions; thus, cytotoxic drugs are used for "consolidation" therapy. Side effects reported during treatment with ATRA include retinoic acid syndrome and Sweet's syndrome. Sweet's syndrome has been associated with acute myelogenous leukemia at presentation, but only two cases of Sweet's syndrome involving the musculoskeletal system in patients treated with ATRA have been described. We describe two additional patients with acute promyelocytic leukemia who had unexplained fever and myalgias (cutaneous lesions in one patient) during induction therapy with ATRA. Radiologic findings were similar to those in previously reported ATRA-associated Sweet's syndrome of the musculoskeletal system. The clinical course was characterized by a rapid resolution of the symptoms during treatment with dexamethasone. Recognition of the syndrome is important, especially considering the rapid resolution of symptoms after early institution of therapy with corticosteroids.

Pyomyositis after chemotherapy for breast cancer

Pyomyositis is a rare complication of chemotherapy. A 47-year-old woman with metastatic breast cancer, in whom pyomyositis developed after chemotherapy, is described. It was difficult to differentiate between pyomyositis and deep venous thrombosis early in her admission. Pyomyositis should be considered part of the differential diagnosis of deep venous thrombosis. This infection, after chemotherapy, usually is considered to be caused by neutropenia or immunodeficiency secondary to the cancer, or both. It is postulated that subclinical myopathy, secondary to the malignancy or drugs used in treating the malignancy, or both, may also predispose to pyomyositis.

Focal myositis: magnetic resonance imaging findings and peripheral arterial administration of prednisolone

We report two patients with biopsy-proven focal myositis, successfully treated with a peripheral arterial injection of low-dose prednisolone. Spin-echo T2-weighted magnetic resonance images helped to identify affected muscles and proved to be useful for monitoring treatment.

Sympathetic skin response in scleroderma, scleroderma overlap syndromes and inflammatory myopathies

Sympathetic skin response (SSR), a non-invasive method for evaluation of the autonomic nervous system, was studied in 57 patients with various connective tissue disorders: scleroderma, dermatomyositis, polymyositis, scleromyositis and unclassified collagenoses. The patients were divided into three main groups: scleroderma (SSc), myositis or other inflammatory myopathy (M) and scleromyositis (ScM). The aim of the study was to detect abnormalities of the SSR in the connective tissue diseases, to define the pattern for each group and to evaluate the usefulness of SSR in detection of subclinical impairment of sympathetic cholinergic function. In the myositis group, an abnormal SSR was found in 88% of patients; the main abnormality was absence of the response from the lower limbs (in 50% of patients). In scleroderma, the SSR was abnormal in 77% of patients, consisting mainly of absence of the response from the lower limbs, whereas responses from the upper limbs were normal. In scleromyositis, the SSR was abnormal in 80% of patients, the most frequent finding was an increase in latency in one limb. The SSR changes were most pronounced in connective tissue disorders with myositis or inflammatory myopathy. The SSR, although non-disease-specific, because of its sensitivity, seems to be useful in the assessment of the abnormalities of the autonomic nervous system in scleroderma and inflammatory myopathies. The study showed a very high prevalence of autonomic nervous system dysfunction in connective tissue diseases associated with myopathy or myositis, displaying no clinical symptoms of autonomic system involvement.

[Fulminant streptococcus infection of soft tissue]

BACKGROUND

In recent years there has been an apparent increase in severe infections produced by group A beta-hemolytic Streptococci in developed countries. Necrotizing fascitis and myositis are two rare but fearsome complications caused by this microorganism.

METHODS

Two cases of fulminant soft tissue infection recently observed in the authors' center are presented and the clinical presentation and differential diagnosis commented upon.

RESULTS

The first case was a necrotizing fascitis at a surgical wound which appeared following a gynecological surgery. The second case reports gluteal myositis following intramuscular injection. In both cases the evolution was disastrous.

CONCLUSIONS

Streptococcus pyogenes may produce fulminant infections in patients without underlying disease either spontaneously or following minimum traumas. The most frequent involvement is of the soft tissues. This virulence at a local tissue and systemic level has been associated with the production of exotoxin.

Benign acute childhood myositis: laboratory and clinical features

BACKGROUND

Benign acute myositis of childhood is a disorder of midchildhood, typically affecting boys. Symptoms include calf pain and difficulty walking after a viral illness. There is an epidemiologic association with influenza.

OBJECTIVES

To describe the clinical and laboratory features of benign acute myositis.

RESULTS

Thirty-eight children (32 boys, 6 girls) were seen with 41 episodes of myositis between 1978 and 1997. Two were siblings and three had recurrent episodes. Mean age at onset of symptoms was 8.1 years. Children remained ambulant during 33 of 41 episodes. Two characteristic gaits were noted: toe-walking in 13, with a wide-based stiff-legged gait in another 7. Muscle tenderness was isolated to the gastrocnemius-soleus muscles in 82% of episodes. Recovery occurred within 1 week. Creatine kinase levels were elevated during all episodes. Viral studies were positive in 10 of 24 episodes, 5 because of influenza B.

CONCLUSION

Benign acute myositis is a syndrome of midchildhood that can be differentiated from more serious causes of walking difficulty by the presence of calf tenderness, normal power, intact tendon reflexes, and elevated creatine kinase. The gait patterns noted may minimize power generation of the calf muscles by splinting the ankles. Onset in childhood may reflect an age-related response to viral infection, and occurrence primarily in boys may reflect a genetic predisposition or an as-yet unknown metabolic defect.

Pyomyositis - clinical and MRI characteristics report of three cases

We report three patients with pyomyositis due to Staphylococcus aureus. Magnetic resonance imaging aided in the accurate diagnosis of the infection and of the extent of involvement. Incision, drainage and antibiotic therapy eradicated the infection in all the patients. We suggest clinical or subclinical bacteraemic seeding of the diseased muscle, as the most likely mechanism for pyomyositis.

Proliferative myositis in a child

A case of proliferative myositis in the lumbar paraspinal muscles in a 14-year-old boy is presented. Imaging investigations including plain radiograph, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), bone scan and positron emission tomography (PET) were suggestive of an inflammatory process such as myositis ossificans. The diagnosis was made by incisional biopsy. More pronounced edema, more muscle fiber necrosis and a higher cellularity were found compared to adult cases. The karyotype of the lesion was normal. Clinically, the mass disappeared spontaneously. After 24 months, asymptomatic bridging ossification between the third and fourth lumbar vertebrae was noted.

S-1 radiculopathy as a possible predisposing factor in focal myositis with unilateral hypertrophy of the calf muscles

Associated with chronic S-1 radiculopathy, a 44-year-old man developed unilateral hypertrophy of the calf muscles. Electromyography revealed neurogenic alterations in the corresponding limb compatible with S-1 radiculopathy. In addition, MR-tomographic and bioptic findings were consistent with a focal inflammatory myopathy of the enlarged right gastrocnemius muscle. Predisposing factors for the localisation of a focal myositis are unknown. This case report highlights the diagnostic difficulties in distinguishing focal myositis and denervation hypertrophy following S-1 radiculopathy or secondary inflammation related to denervation. We consider the possibility that in our case the inflammatory process might have been triggered by electromyographically proven chronic denervation related to radiculopathy.