Infection and musculoskeletal conditions: Infectious myositis

Infectious myositis, an infection of the skeletal muscle(s), is uncommon. This clinical entity may be caused by viral, bacterial, fungal, and parasitic pathogens. Viral etiologies typically cause diffuse myalgias and/or myositis, whereas bacteria and fungi usually lead to a local myositis which may be associated with sites compromised by trauma or surgery and are more common among immunocompromised patients. Localized collections within the muscles are referred to as pyomyositis. Other pyogenic causes of myositis include gas gangrene, group A streptococcal myonecrosis, and other types of non-clostridial myonecrosis. Early recognition and treatment of these conditions are necessary as they may rapidly become life-threatening.     

Pyomyositis mimicking leptospirosis: two cases in a Brazilian tertiary care hospital in a non-tropical area

Pyomyositis is a subacute, deep suppurative bacterial infection of skeletal muscle not arising from contiguous infection. It is presumably haematogenous in origin, and characterized by muscle pain and swelling. We report on two patients who presented with pyomyositis in a tertiary care hospital in temperate region located in southern Brazil with a clinical presentation, which was initially suggestive of leptospirosis. This report discusses the pathogenesis, clinical presentation, diagnosis and management of pyomyositis. Physicians living in non-tropical areas should note that pyomyositis might occur in those areas, and its initial clinical presentation may be similar to leptospirosis.     

Rapidly propagating descending necrotizing mediastinitis as a consequence of intravenous drug use

Descending necrotizing mediastinitis (DNM) is a devastating complication of cervical or odontogenic infections that can spread downward to the mediastinum through anatomic spaces. We report the case of an intravenous drug user who presented with rapidly propagating acute pericarditis and DNM as the early presentations of pyomyositis of the sternocleidomastoid muscle and deep neck infection. The patient was successfully treated with antibiotics and surgical drainage. Clinicians should be aware that pathogens injected into the carotid sheath may spread to the mediastinum and/or pericardium and manifest as DNM and/or pericarditis prior to infectious signs and symptoms at the site of injection.     

Group B streptococcal meningitis revealing an inner ear congenital malformation. A case report in an adult]

INTRODUCTION: Group B streptococcal meningitis is unusual in adults. It occurs in patients with a chronic disease. EXEGESIS: We report a case of group B streptococcal meningitis that occurred in a 32-year-old woman, uncovering inner ear congenital malformation associated with cerebrospinal fluid fistula. There was no recurrent episode of meningitis during a 2-year period following surgical correction of the malformation. CONCLUSION: Clinical signs suggesting cerebrospinal fluid fistula should be considered in any adult patient with severe group B streptococcal infection.     

Painful syndromes in diabetic patients due to skeletal muscle injuries

Progressive painful syndromes due to skeletal muscle injuries rather than diabetic neuropathy are unusual complications of diabetes mellitus (DM). Two clinical cases are presented: Case 1 (pyomyositis: leg location) and Case 2 (muscle infarction: thigh location). Discussion on how to proceed the diagnosis based on clinical features are included as it is critical for early and proper treatment since approaches highly differ in the two situations. These complications can mimic thrombophlebitis, rhabdomyolyses or a neoplasm, therefore the diagnosis of a diabetes-related disorder may be overlooked. If pyomyositis is not correctly treated with antibiotics and in some cases with surgery, systemic infection and even death may occur, whereas muscle infarction only requires rest and analgesia. Image and laboratory investigations can be of help to differentiate these syndromes, although some findings can overlap. Thus, the present report emphasizes the importance to include these diseases when limb painful syndromes are to be investigated in a diabetic patient.     

Necrotizing fasciitis in adults due to group B streptococcus. Report of a case and review of the literature

Necrotizing fasciitis is an uncommon severe infection involving subcutaneous tissues and advancing along fascial planes. Group B streptococcal infections occur disproportionately in diabetics and pregnant women. Although fasciitis secondary to group B streptococcus has been described in infants and adult women in the postpartum period, we report the first case, to our knowledge, of group B streptococcal necrotizing fasciitis in an adult diabetic unrelated to obstetric complications.     

Pyomyositis in patients with diabetes mellitus

Pyomyositis is a pyogenic infection of skeletal muscle that is endemic in the tropics and is being recognized with increasing frequency in temperate climates. We report two cases of nonendemic pyomyositis in patients with diabetes mellitus. A review of the literature suggests that diabetes mellitus may be an important risk factor for the development of pyomyositis. Possible mechanisms of this association are discussed.     

Tropical and temperate pyomyositis

Pyomyositis is a primary infection of skeletal muscle not arising from contiguous infection, presumably hematogenous in origin, and often, but not invariably, associated with abscess formation. Classically, pyomyositis is an infection of the tropics, occurring in previously active and healthy young men. Pyomyositis in temperate countries is often regarded as an infection that occurs in hosts who are immunocompromised or otherwise debilitated. However,this distinction may be somewhat artificial, as tropical pyomyositis may be partly related to underlying infection with HIV or parasites, and temperate pyomyositis has been reported in healthy and athletic persons. This article discusses the pathogenesis, clinical presentation, diagnosis, and management of pyomyositis in the tropical and temperate settings.     

Pyomyositis in North America: case reports and review.

We report two cases and review the characteristics of pyomyositis. The courses of patients who presented with pyomyositis at the Maricopa Medical Center (Phoenix) are detailed. Ninety-eight reported cases over the last 20 years in North America, found through a MEDLINE search, are summarized. Infection with the human immunodeficiency virus (HIV) may predispose the patient to pyomyositis. The onset is usually insidious with progression to large purulent collections and significant morbidity. The diagnosis is frequently suggested by findings of imaging studies. Staphylococcus aureus is responsible for most cases in tropical areas but is less frequently associated with cases in North America. Since infection with HIV predisposes patients to bacterial infections, pyomyositis will occur more frequently in this patient population. Increased awareness of the disease will improve management. Following aspiration or surgical drainage, therapy with broad-spectrum empirical antibiotics may be considered initially in the treatment of pyomyositis.     

Streptococcal myositis

Two patients had streptococcal myositis. Both patients developed extensive muscle necrosis and overwhelming sepsis after trivial skin trauma. Death occurred within 48 hours of hospital admission despite aggressive surgical and medical treatment. Review of the literature is included to highlight the fulminant nature of this unusual infection and to contrast streptococcal myositis with other soft-tissue streptococcal infections.     

Stenotrophomonas maltophilia: a very rare cause of tropical pyomyositis

Pyomyositis is a purulent infection of skeletal muscles that arise from hematogenous spread associated with abscess formation. Most often caused by Staphylococcus aureus in more than 90–95% of cases but other rare organisms can cause this infection. Herein we report a rare case of strenotrophomonas maltophilia as a cause of pyomyositis which is a rare occurrence, especially in immunocompetent adults. Strenotrophomonas is a multidrug‐resistant aerobic non‐fermentative, non‐sporulating, Gram‐negative bacillus which usually produces nosocomial infections, but community‐acquired infections are also rarely reported. This a first case report of strenotrophomonas maltophilia causing pyomyositis in an immunocompetent adult.     

Invasive group A streptococcus infections.

The late 1980s have witnessed the emergence of severe group A streptococcus (GAS) infection; shock, bacteremia, and acute respiratory distress syndrome are common features, and death has been associated with this infection in 30% of patients. Such infections have now been described in all parts of the United States, Europe, and Australia and have occurred predominantly in otherwise healthy adolescents and adults. The characteristic clinical and laboratory features of the streptococcal toxic shock syndrome include deep-seated infection associated with shock and multiorgan failure. Strains of GAS isolated from patients with invasive disease have been predominantly M types 1 and 3, which produce pyrogenic exotoxin A or B or both. In this report, the clinical and demographic features of streptococcal bacteremia, myositis, and necrotizing fasciitis will be presented and compared with those of streptococcal toxic shock syndrome. Current concepts of the pathogenesis of invasive streptococcal infection will also be presented in terms of the interaction between virulence factors of GAS and host defense mechanisms. Finally, new concepts for future treatment of serious streptococcal infections will be proposed.     

Tuberculous pyomyositis in a renal transplant recipient.

Infections are a major cause of morbidity and mortality in renal transplant recipients. Although these patients are susceptible to many types of infection, soft tissue infections are rare. We report a case of tuberculous pyomyositis involving the left erector spinae muscle but with no other manifestations of tuberculosis. The diagnosis was suspected from the CT scan appearance and confirmed by microscopy and culture of the pus. Surgical incision and drainage, together with antituberculosis therapy, cured the infection. The relevant literature is briefly reviewed.     

Group B streptococcal bacteremia in an adult: a case report from India

The incidence of group B streptococcal bacteremia in adults has increased in recent years, particularly in patients with severe underlying diseases. However, group B still remains an unusual pathogen in adults in developing countries. We report a case of group B streptococcal bacteremia in a non-pregnant adult, the only case reported in our hospital. The organism was only isolated from the blood and responded to specific therapy.     

An uncommon spontaneous and nontropical pyomyositis

We describe a case of pyomyositis of the thigh caused by Staphylococcus epidermidis in an immunocompetent patient. The outcome was favorable after initiation of treatment combining surgical debridement of muscle abscesses and appropriate antibiotic therapy for a 4-week period. Our case report underlines that magnetic resonance imaging (MRI) may be a helpful method in the management of pyomyositis, in accurately revealing the detailed anatomic extent of the abscessed pyomyositis, and in guiding the surgical debridement of the damaged muscle. Finally, MRI should be performed if there is a strong suspicion of pyomyositis in patients whose ultrasonographic examination is not conclusive.     

Skin and soft tissue infections

Primary skin infections (ie, pyodermas) typically are initiated by some breach in the epidermis, resulting in infection by organisms, such as Streptococcus pyogenes and Staphylococcus aureus, that normally colonize the skin. Host-associated factors, such as immunosuppression, vasculopathy, neuropathy, or decreased lymphatic drainage, may predispose to skin infection. The clinical syndromes associated with skin infections are often characteristic and are defined most simplistically by anatomic distribution. Although often mild and self-limited, skin infections can be more aggressive and involve deeper structures, including fascia and muscle. This article discusses skin and soft tissue infections, including impetigo, hair follicle-associated infections (ie, folliculitis, furuncles, and carbuncles) erysipelas, cellulitis, necrotizing fasciitis, pyomyositis, septic bursitis, and tenosynovitis.     

Invasive group A streptococcal infections.

Beginning in the mid-1980s and continuing to the present, there has been an apparent increase in the number of severe group A streptococcal infections and their suppurative and nonsuppurative sequelae. The reasons for this epidemiologic change remain incompletely explained. At present, the data seem to suggest that this change is related to the reappearance in the population of not only "new" serotypes, but most likely virulent strains of these serotypes. This has been suggested by available epidemiologic surveys. The pathogenetic mechanism by which these virulent strains cause an increased severity of disease is also incompletely understood. It has been suggested that certain of the streptococcal pyrogenic exotoxins (pyrogenic exotoxin A or B) are associated with strains isolated from severe cases of systemic group A streptococcal infections, but the data conflict in many instances. Clinically, this is an extraordinarily virulent syndrome often leading to the death of the patient within a matter of hours or days. This is despite what would seem to be adequate and appropriate antimicrobial therapy with agents which are effective in vitro against the offending group A streptococcus. Therapy therefore is still based on appropriate antibiotic therapy and support of other systemic manifestations with appropriate medical therapy. At present, prevention of these suppurative and nonsuppurative sequelae is impractical simply because the initial streptococcal infection or colonization is rarely recognized. These events of the last half decade strongly support the need for additional understanding of the epidemiology, pathogenesis, treatment, and prevention of serious group A beta-hemolytic streptococcal infections.     

Pyomyositis in patients with the human immunodeficiency virus: an unusual form of disseminated bacterial infection

PURPOSE AND PATIENTS: Pyomyositis, a common disease in the tropics, is rare in the continental United States, with approximately 83 cases described in the literature in the past two decades. The occurrence of pyomyositis complicating human immunodeficiency virus (HIV) infection has been reported in 10 patients since 1986. We report six cases of this entity in patients with advanced HIV disease seen in our institution over a 20-month period. A common denominator in all of our patients was muscle injury, induced by either exercise or trauma. Unlike most previous reports of HIV-associated pyomyositis, the clinical picture in our cases was complicated by the development of abscesses in multiple muscle groups, requiring prolonged antimicrobial therapy and repeated drainage procedures for successful management. Interestingly, one patient developed concomitant rhabdomyolysis--an otherwise rare event in classical pyomyositis. Staphylococcus aureus was the predominant infecting organism in this as well as all other series. Of note, we also observed and report the first case, to our knowledge, of gram-negative pyomyositis in an HIV-infected individual. The pathogenic implications of this catalase-producing gram-negative isolate are discussed in the context of neutrophil abnormalities in HIV disease. CONCLUSION: Like tropical pyomyositis, its HIV-associated counterpart appears to be multifactorial in origin. Its recent recognition suggests that, in addition to underlying abnormalities of host defense, factors relating to the prolonged survival of patients with late-stage disease, including myopathy, might play an important contributory role.     

Recurrent group A Streptococcal genital infection after Puerperal sepsis

Recurrent group A streptococcal infection is a well-known phenomenon. It is well documented as a problem in pharyngotonsillitis and skin infections. This report describes a case of recurrent genital infection after puerperal sepsis caused by group A streptococci.     

Association of common variable immunodeficiency with atypical collagenous colitis

Collagenous colitis is a condition characterized by chronic, watery diarrhoea, which is diagnosed histologically as most cases reveal a normal colonoscopic appearance. The aetiology is poorly understood, but nonsteroidal anti-inflammatory drugs or infections may act as triggers for an immune-mediated process. In this report, an unusual case of collagenous colitis associated with pseudomembrane formation is described. Stool assay was negative for Clostridium difficile cytotoxin B. There are only three reports of pseudomembranes in collagenous colitis in the absence of C. difficile infection. In addition, the patient had a deficiency in immunoglobulin production, which may suggest an infective trigger to collagenous colitis. This is the first report of an association between an immunoglobulin deficiency and this unusual variant of collagenous colitis. The implications of these findings are discussed.