A current approach to diabetic foot infections

Foot infections are a common, complex, and serious problem in diabetic patients. Infections usually begin in foo ulcers, which are associated with neuropathy, vasculopathy, and various metabolic disturbances. These infections are potentially limb and sometimes life threatening. Etiologic agents are usually aerobic gram-positive cocci, but chronic or serious infections often contain gram-negative rods and anaerobes. Chronic infections can lead to contiguous bone infection. Diagnosing osteomyelitis may require imaging studies (especially magnetic resonance imaging) and occasionally bone biopsy. In addition to proper cleansing, debridement, and local wound care, diabetic foot infections require carefully selected antibiotic therapy. Serious infections necessitate hospitalization for initial parenteral broad-spectrum antibiotic therapy, but appropriately selected patients with mild infections can be treated as outpatients with oral (or even topical) agents. Initial antibiotic selection is usually empiric; modifications may be needed based on the results of properly obtained cultures and the clinical response. Therapy should be active against staphylococci and streptococci, with broader-spectrum agents indicated if polymicrobial infection is likely. Levels of most antibiotics, except fluoroquinolones, are often subtherapeutic in infected foot tissues. The duration of therapy ranges from a week (for mild soft tissue infections) to over 6 weeks (for osteomyelitis). No single antibiotic agent or combination has proven to be optimal. With appropriate local, surgical, and antimicrobial therapy, most diabetic foot infections can now be successfully treated.     

Expert opinion on the management of infections in the diabetic foot

This update of the International Working Group on the Diabetic Foot incorporates some information from a related review of diabetic foot osteomyelitis (DFO) and a systematic review of the management of infection of the diabetic foot. The pathophysiology of these infections is now well understood, and there is a validated system for classifying the severity of infections based on their clinical findings. Diagnosing osteomyelitis remains difficult, but several recent publications have clarified the role of clinical, laboratory and imaging tests. Magnetic resonance imaging has emerged as the most accurate means of diagnosing bone infection, but bone biopsy for culture and histopathology remains the criterion standard. Determining the organisms responsible for a diabetic foot infection via culture of appropriately collected tissue specimens enables clinicians to make optimal antibiotic choices based on culture and sensitivity results. In addition to culture-directed antibiotic therapy, most infections require some surgical intervention, ranging from minor debridement to major resection, amputation or revascularization. Clinicians must also provide proper wound care to ensure healing of the wound. Various adjunctive therapies may benefit some patients, but the data supporting them are weak. If properly treated, most diabetic foot infections can be cured. Providers practising in developing countries, and their patients, face especially challenging situations.     

Foot ulceration and infections in elderly diabetics

Foot lesions occur commonly among patients with diabetes, particularly the elderly and those with sensory neuropathy. Because of serious or recurrent infections and impaired healing processes, initially trivial lesions may progress to chronic nonhealing wounds, gangrene, or untreatable infections that can lead to limb amputation. Strategies to prevent amputation depend on understanding the multifactorial nature of diabetic foot disease; providing effective ongoing preventive care, including patient education; and prompt and aggressive treatment of foot lesions when they occur. The approach to treatment of infections depends on many factors, including the severity of the soft tissue infection, whether or not underlying bone or joints are involved, the types of infecting organisms, the patient's social situation, and his other medical problems. Proper diagnostic studies followed by appropriate antimicrobial therapy and local wound care can usually lead to resolution of these potentially serious infections.     

Diagnosing diabetic foot osteomyelitis

Bone involvement during an infection of the diabetic foot represents a serious complication associated with a high risk of amputation, prolonged antibiotic treatment and hospitalization. Diabetic foot osteomyelitis (DFOs) require a multidisciplinary approach given the usual complexity of these situations. DFO should be suspected in most cases especially in the most severe forms of soft tissue diabetic foot infections (DFIs) where the prevalence of bone infection may be up to 60%. Suspicion is based on clinical signs in particular a positive probe‐to‐bone (PTB) test, elevated inflammatory biomarkers especially erythrocyte sedimentation rate and abnormal imaging assessment using plain X‐ray as a first‐line choice. The combination of PTB test with plain X‐ray has proven effective in the diagnosis of DFO. The confirmation (definite) diagnosis of DFO is based on the results of a bone sample examination obtained by either surgical or percutaneous biopsy. Sophisticated imaging examinations such as Magnetic Resonance Imaging (MRI) and nuclear imaging techniques are useful where doubt persists after first‐line imaging assessment. These techniques may also help localize the bone infection site and increase the diagnostic performance of percutaneous bone biopsy. The quality of the microbiological documentation of DFO is likely to improve the adequacy of the antimicrobial therapy especially when medical (ie, no surgical resection of the infected bone tissues) is considered. The use of new (molecular) techniques for the identification of the bone pathogens have not yet proven superiority on classic cultural techniques for the management of such patients.     

Advances in the treatment of diabetic foot infections

Lower extremity infections are frequent causes of substantial morbidity and mortality in the diabetic population, and these infections consume a large portion of resources expended on diabetic complications. Gram-positive cocci, particularly Staphylococcus aureus, are the most important pathogens in diabetic foot infections. These organisms are predominant both in mild infections (which are often monomicrobial), as well as in more severe and chronic infected wounds that more often have a polymicrobial cause. Appropriate clinical assessment and culturing of infections are critical in establishing the presence and severity of infection, in detecting osteomyelitis, and in directing the optimal treatment approach. Following necessary debridement and other surgical interventions (e.g., bone resection, revascularization), appropriate antibiotic therapy is a cornerstone of managing the infected lower extremity. Peripheral vascular (i.e., arterial) insufficiency and the increasing prevalence of antibiotic resistance are primary barriers to successfully managing these infections. Fortunately, alternative delivery systems (e.g., antibiotic beads, impregnated sponges) and novel antibiotics (e.g., levofloxacin, linezolid) are providing possible solutions to the challenges posed by this physically, emotionally, and financially devastating condition.     

A case of group B streptococcal pyomyositis

The group B streptococcus is an opportunistic pathogen that causes a variety of serious infections including bacteremias, puerperal sepsis, and neonatal meningitis. Group B streptococcal infections of muscle are rare. We report here an unusual case of group B streptococcal pyomyositis. Pyomyositis arises predominantly from infections caused by Staphylococcus aureus and, occasionally, Streptococcus pyogenes. Because of the rarity of pyomyositis in temperate climates, the common lack of localizing signs or symptoms, and the frequently negative blood cultures, considerable delay often precedes the diagnosis of pyomyositis; in fact, the infection has been initially misdiagnosed as muscle hematoma, cellulitis, thrombophlebitis, osteomyelitis, or neoplasm. Diagnosis may be greatly aided by radiologic techniques that can demonstrate the sites of muscle enlargement and the presence of fluid collections. The response to antibiotics is usually rapid, but resolution of the infection may require aspiration of deeply situated muscle abscesses. This report describes a diabetic patient with an unusual presentation of pyomyositis that mimicked an acute abdomen.     

2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections

Foot infections are a common and serious problem in persons with diabetes. Diabetic foot infections (DFIs) typically begin in a wound, most often a neuropathic ulceration. While all wounds are colonized with microorganisms, the presence of infection is defined by ≥2 classic findings of inflammation or purulence. Infections are then classified into mild (superficial and limited in size and depth), moderate (deeper or more extensive), or severe (accompanied by systemic signs or metabolic perturbations). This classification system, along with a vascular assessment, helps determine which patients should be hospitalized, which may require special imaging procedures or surgical interventions, and which will require amputation. Most DFIs are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, the most common causative organisms. Aerobic gram-negative bacilli are frequently copathogens in infections that are chronic or follow antibiotic treatment, and obligate anaerobes may be copathogens in ischemic or necrotic wounds. Wounds without evidence of soft tissue or bone infection do not require antibiotic therapy. For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic and anaerobic culture. Empiric antibiotic therapy can be narrowly targeted at GPC in many acutely infected patients, but those at risk for infection with antibiotic-resistant organisms or with chronic, previously treated, or severe infections usually require broader spectrum regimens. Imaging is helpful in most DFIs; plain radiographs may be sufficient, but magnetic resonance imaging is far more sensitive and specific. Osteomyelitis occurs in many diabetic patients with a foot wound and can be difficult to diagnose (optimally defined by bone culture and histology) and treat (often requiring surgical debridement or resection, and/or prolonged antibiotic therapy). Most DFIs require some surgical intervention, ranging from minor (debridement) to major (resection, amputation). Wounds must also be properly dressed and off-loaded of pressure, and patients need regular follow-up. An ischemic foot may require revascularization, and some nonresponding patients may benefit from selected adjunctive measures. Employing multidisciplinary foot teams improves outcomes. Clinicians and healthcare organizations should attempt to monitor, and thereby improve, their outcomes and processes in caring for DFIs.     

Executive summary: 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections

Foot infections are a common and serious problem in persons with diabetes. Diabetic foot infections (DFIs) typically begin in a wound, most often a neuropathic ulceration. While all wounds are colonized with microorganisms, the presence of infection is defined by ≥2 classic findings of inflammation or purulence. Infections are then classified into mild (superficial and limited in size and depth), moderate (deeper or more extensive), or severe (accompanied by systemic signs or metabolic perturbations). This classification system, along with a vascular assessment, helps determine which patients should be hospitalized, which may require special imaging procedures or surgical interventions, and which will require amputation. Most DFIs are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, the most common causative organisms. Aerobic gram-negative bacilli are frequently copathogens in infections that are chronic or follow antibiotic treatment, and obligate anaerobes may be copathogens in ischemic or necrotic wounds. Wounds without evidence of soft tissue or bone infection do not require antibiotic therapy. For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic and anaerobic culture. Empiric antibiotic therapy can be narrowly targeted at GPC in many acutely infected patients, but those at risk for infection with antibiotic-resistant organisms or with chronic, previously treated, or severe infections usually require broader spectrum regimens. Imaging is helpful in most DFIs; plain radiographs may be sufficient, but magnetic resonance imaging is far more sensitive and specific. Osteomyelitis occurs in many diabetic patients with a foot wound and can be difficult to diagnose (optimally defined by bone culture and histology) and treat (often requiring surgical debridement or resection, and/or prolonged antibiotic therapy). Most DFIs require some surgical intervention, ranging from minor (debridement) to major (resection, amputation). Wounds must also be properly dressed and off-loaded of pressure, and patients need regular follow-up. An ischemic foot may require revascularization, and some nonresponding patients may benefit from selected adjunctive measures. Employing multidisciplinary foot teams improves outcomes. Clinicians and healthcare organizations should attempt to monitor, and thereby improve, their outcomes and processes in caring for DFIs.     

Diabetic foot osteomyelitis

Bone infection in the diabetic foot is always a complication of a preexisting infected foot wound. Prevalence can be as high as 66%. Diagnosis can be suspected in two mains conditions: no healing (or no depth decrease) in spite of appropriate care and off-loading, and/or a visible or palpated bone with a metal probe. The first recommended diagnostic step is to perform (and if necessary to repeat) plain radiographs. After a four-week treatment period, if plain radiographs are still normal, suspicion for bone infection will persist in case of bad evolution despite optimized management of off-loading and arterial disease. It is only in such cases that other diagnosis methods than plain radiographs must be used. Staphylococcus aureus is the most common pathogen cultured from bone samples, followed by Staphylococcus epidermidis. Among enterobacteriaceae, Escherichia coli, Klebsiella pneumonia and Proteus sp. are the most common, followed by Pseudomonas aeruginosa. Surprisingly, bacteria usually considered contaminant (as coagulase negative staphylococci (CNS) and Corynebacterium sp.) have been documented to be pathogens in the osteomyelitis of diabetic foot. Traditional approach to treatment of chronic osteomyelitis was by surgical resection of infected and necrotic bone. But new classes of antibiotics have both the required spectrum of activity and the capacity to penetrate and concentrate in the infected bone. Recently, several observations of osteomyelitis remission following non-surgical management with a prolonged course of antibiotics have been published. Lastly, combined approach with local bone excision and antibiotics has been proposed. Prospective trials should be undertaken to determine the relative roles of surgery and antibiotics in managing diabetic foot osteomyelitis.     

Osteomyelitis

Bone and joint infections are painful for patients and frustrating for both them and their doctors. The high success rates of antimicrobial therapy in most infectious diseases have not yet been achieved in bone and joint infections owing to the physiological and anatomical characteristics of bone. The key to successful management is early diagnosis, including bone sampling for microbiological and pathological examination to allow targeted and long-lasting antimicrobial therapy. The various types of osteomyelitis require differing medical and surgical therapeutic strategies. These types include, in order of decreasing frequency: osteomyelitis secondary to a contiguous focus of infection (after trauma, surgery, or insertion of a joint prosthesis); that secondary to vascular insufficiency (in diabetic foot infections); or that of haematogenous origin. Chronic osteomyelitis is associated with avascular necrosis of bone and formation of sequestrum (dead bone), and surgical debridement is necessary for cure in addition to antibiotic therapy. By contrast, acute osteomyelitis can respond to antibiotics alone. Generally, a multidisciplinary approach is required for success, involving expertise in orthopaedic surgery, infectious diseases, and plastic surgery, as well as vascular surgery, particularly for complex cases with soft-tissue loss.     

Challenges in diagnosing infection in the diabetic foot

Diagnosing the presence of infection in the foot of a patient with diabetes can sometimes be a difficult task. Because open wounds are always colonized with microorganisms, most agree that infection should be diagnosed by the presence of systemic or local signs of inflammation. Determining whether or not infection is present in bone can be especially difficult. Diagnosis begins with a history and physical examination in which both classic and ‘secondary’ findings suggesting invasion of microorganisms or a host response are sought. Serological tests may be helpful, especially measurement of the erythrocyte sedimentation rate in osteomyelitis, but all (including bone biomarkers and procalcitonin) are relatively non‐specific. Cultures of properly obtained soft tissue and bone specimens can diagnose and define the causative pathogens in diabetic foot infections. Newer molecular microbial techniques, which may not only identify more organisms but also virulence factors and antibiotic resistance, look very promising. Imaging tests generally begin with plain X‐rays; when these are inconclusive or when more detail of bone or soft tissue abnormalities is required, more advanced studies are needed. Among these, magnetic resonance imaging is generally superior to standard radionuclide studies, but newer hybrid imaging techniques (single‐photon emission computed tomography/computed tomography, positron emission tomography/computed tomography and positron emission tomography/magnetic resonance imaging) look to be useful techniques, and new radiopharmaceuticals are on the horizon. In some cases, ultrasonography, photographic and thermographic methods may also be diagnostically useful. Improved methods developed and tested over the past decade have clearly increased our accuracy in diagnosing diabetic foot infections.     

Peculiarities of osteo-articular infections in children.

Paediatric osteomyelitis is uncommon in the developed world, haematogenous spread of infection being the most prevalent cause in children. The metaphyses of the long bones are the sites involved in most cases, but in neonates the infection may spread to the contiguous epiphysis and joint. Staphylococcus aureus is the main causal organism in all groups. Plain X-rays take at least 7 days to show the first signs of osteomyelitis. Bone scans show change earlier, with a high sensitivity but a lower specificity. Magnetic resonance imaging and computed tomography are useful, if expensive, imaging techniques but usually require sedation in children. The causal micro-organisms may be identified from blood cultures, fine-needle aspiration or surgical drainage. Antimicrobial therapy should be given for 3-4 weeks, initially via the intravenous route and later switching to oral medication. Surgery is indicated for the drainage of acute abscesses or when there has been no improvement with antibiotics; it is essential in the treatment of chronic osteomyelitis.     

Antibiotic agents in the elderly

Changes that occur in the pharmacology of drugs in the elderly must be considered in the use of antimicrobial agents. Although absorption of orally administered drugs is not affected in a significant way, renal function decreases, drug-drug interactions increase, compliance with regimens may be decreased, and drug toxicity is increased. The most frequent infections occurring in the elderly are pneumonia, urinary tract infection, and soft-tissue infection. CDAD is usually a complication of antibiotic therapy. Pneumonia can be categorized as community-acquired, LTCF, and hospital-acquired. Therapeutic approaches vary according to which of these sites is involved. Urinary tract infection is divided into upper tract infection, lower tract infection, and asymptomatic bacteriuria. Upper tract infection is treated for a longer period than lower tract infection; with few exceptions, asymptomatic bacteriuria is usually not treated. Soft-tissue infection is usually caused by an infected pressure ulcer or cellulitis (which may be a complication of a diabetic foot ulcer or an ulcer due to peripheral vascular disease). These infections have different microbial causes and require different therapeutic approaches.     

Osteomyelitis in the diabetic patient: diagnosis and treatment. Part 2: Medical, surgical, and alternative treatments

In the diabetic population, wound and foot infections are often mixed, containing from three to six organisms. This creates a significant problem regarding antibiotic protocols. Many of these episodes result in contiguous bone infections with subsequent erosive changes, sequestra, and involucrum. A multidisciplinary approach to treatment is often required. Studies have shown that a protocol of 6 weeks of intravenous antibiotics may be appropriate to treat osteomyelitis; however, this is controversial and often not curative. Osteomyelitis is a surgical disease; a subtle balance between medical and surgical therapy is necessary if a potentially curative outcome is to be achieved. The duration of antibiotic therapy may be shortened considerably after surgical intervention. In cases of infection mitigated by severe peripheral vascular disease, end-stage renal disease, diabetes, or other medical problems where surgery is not an option, long-term antibiotics may be used as suppressive therapy along with adjunctive local treatments. The following is the second article of a two-part series. The first paper discussed the diagnosis and microbiology of contiguous osteomyelitis in the diabetic foot. This article outlines the various medical, antibiotic, and surgical options available to the clinician. Adjunctive and alternative therapies also are discussed.     

Disseminated histoplasmosis in the acquired immune deficiency syndrome: clinical findings, diagnosis and treatment, and review of the literature

Histoplasmosis is a serious opportunistic infection in patients with AIDS, often representing the first manifestation of the syndrome. Most infections occurring within the endemic region are caused by exogenous exposure, while those occurring in nonendemic areas may represent endogenous reactivation of latent foci of infection or exogenous exposure to microfoci located within those nonendemic regions. However, prospective investigations are needed to prove the mode of acquisition. The infection usually begins in the lungs even though the chest roentgenogram may be normal. Clinical findings are nonspecific; most patients present with symptoms of fever and weight loss of at least 1 month's duration. When untreated, many cases eventually develop severe clinical manifestations resembling septicemia. Chest roentgenograms, when abnormal, show interstitial or reticulonodular infiltrates. Many cases have been initially misdiagnosed as disseminated mycobacterial infection or Pneumocystis carinii pneumonia. Patients are often concurrently infected with other opportunistic pathogens, supporting the need for a careful search for co-infections. Useful diagnostic tests include serologic tests for anti-H. capsulatum antibodies and HPA, silver stains of tissue sections or body fluids, and cultures using fungal media from blood, bone marrow, bronchoalveolar lavage fluid, and other tissues or body fluids suspected to be infected on clinical grounds. Treatment with amphotericin B is highly effective, reversing the clinical manifestations of infection in at least 80% of cases. However, nearly all patients relapse within 1 year after completing courses of amphotericin B of 35 mg/kg or more, supporting the use of maintenance treatment to prevent recurrence. Relapse rates are lower (9 to 19%) in patients receiving maintenance therapy with amphotericin B given at doses of about 50 mg weekly or biweekly than with ketoconazole (50-60%), but controlled trials comparing different maintenance regimens have not been conducted. Until results of such trials become available, our current approach is to administer an induction phase of 15 mg/kg of amphotericin B given over 4 to 6 weeks, followed by maintenance therapy with 50 to 100 mg of amphotericin B given once or twice weekly, or biweekly. If results of a prospective National Institutes of Allergy and Infectious Disease study of itraconazole maintenance therapy document its effectiveness, alternatives to amphotericin B may be reasonable.     

Role of antibiotic therapy in diabetic foot management

Antibiotic therapy is not the most important component in diabetic foot ulcer management which should be based on weight bearing avoidance and arterial revascularization. However antibiotic therapy is necessary in presence of extensive deep involvement or systemic signs of infection. Initial antimicrobial treatment depends on bacteria supposed origin. For patients not coming from hospital, the initial choice antibiotic is an amoxicillin/clavulanate agent because it offers optimal coverage for most pathogens involved in those diabetic foot lesions (gram positive cocci, gram negative and anaerobic organisms). For patients at high risk to be infected with nosocomially acquired pathogens, the initial antibiotic therapy must cover methicillin-resistant staphylococci, resistant pseudomonas aeruginosa or enterobacteriae. In all cases, when definitive reliable cultures are reported, initial antibiotic regimens should be revised to narrow the coverage to specific pathogens. In presence of osteomyelitis, a temporary combination of two agents which are known to reach high bone concentrations is necessary, and antibiotic therapy should be continued for at least two months. In other cases, antibiotic treatment duration depends on clinical out come.     

Central nervous system infections in the compromised host: a diagnostic approach.

The diagnostic approach to the compromised host with CNS infection depends on an analysis of the patient's clinical manifestations of CNS disease, the acuteness or subacuteness of the clinical presentation, and an analysis of the type of immune defect compromising the patient's host defenses. Most patients with CNS infections may be grouped into those with meningeal signs, or those with mass lesions. Other common manifestations of CNS infection include encephalopathy, seizures, or a stroke-like presentation. Most pathogens have a predictable clinical presentation that differs from that of the normal host. CNS Aspergillus infections present either as mass lesions (e.g., brain abscess), or as cerebral infarcts, but rarely as meningitis. Cryptococcus neoformans, in contrast, usually presents as a meningitis but not as a cerebral mass lesion even when cryptococcal elements are present. Aspergillus and Cryptococcus CNS infections are manifestations of impaired host defenses, and rarely occur in immunocompetent hosts. In contrast, the clinical presentation of Nocardia infections in the CNS is the same in normal and compromised hosts, although more frequent in compromised hosts. The acuteness of the clinical presentation coupled with the CNS symptomatology further adds to limit differential diagnostic possibilities. Excluding stroke-like presentations, CNS mass lesions tend to present subacutely or chronically. Meningitis and encephalitis tend to present more acutely, which is of some assistance in limiting differential diagnostic possibilities. The analysis of the type of immune defect predicts the range of possible pathogens likely to be responsible for the patient's CNS signs and symptoms. Patients with diseases and disorders that decrease B-lymphocyte function are particularly susceptible to meningitis caused by encapsulated bacterial pathogens. The presentation of bacterial meningitis is essentially the same in normal and compromised hosts with impaired B-lymphocyte immunity. Compromised hosts with impaired T-lymphocyte or macrophage function are prone to develop CNS infections caused by intracellular pathogens. The most common intracellular pathogens are the fungi, particularly Aspergillus, other bacteria (e.g., Nocardia), viruses (i.e., HSV, JC, CMV, HHV-6), and parasites (e.g., T. gondii). The clinical syndromic approach is most accurate when combining the rapidity of clinical presentation and the expression of CNS infection with the defect in host defenses. The presence of extra-CNS sites of involvement also may be helpful in the diagnosis. A patient with impaired cellular immunity with mass lesions in the lungs and brain that have appeared subacutely or chronically should suggest Nocardia or Aspergillus rather than cryptococcosis or toxoplasmosis. Patients with T-lymphocyte defects presenting with meningitis generally have meningitis caused by Listeria or Cryptococcus rather than toxoplasmosis or CMV infection. The disorders that impair host defenses, and the therapeutic modalities used to treat these disorders, may have CNS manifestations that mimic infections of the CNS clinically. Clinicians must be ever vigilant to rule out the mimics of CNS infections caused by noninfectious etiologies. Although the syndromic approach is useful in limiting diagnostic possibilities, a specific diagnosis still is essential in compromised hosts in order to describe effective therapy. Bacterial meningitis, cryptococcal meningitis, and tuberculosis easily are diagnosed accurately from stain, culture, or serology of the CSF. In contrast, patients with CNS mass lesions usually require a tissue biopsy to arrive at a specific etiologic diagnosis. In a compromised host with impaired cellular immunity in which the differential diagnosis of a CNS mass lesion is between TB, lymphoma, and toxoplasmosis, a trial of empiric therapy is warranted. Antitoxoplasmosis therapy may be initiated empirically and usually results in clinical improvement after 2 to 3 weeks of therapy. The nonresponse to antitoxoplasmosis therapy in such a patient would warrant an empiric trial of antituberculous therapy. Lack of response to anti-Toxoplasma and antituberculous therapy should suggest a noninfectious etiology (e.g., CNS lymphoma). Fortunately, most infections in compromised hosts are similar in their clinical presentation to those in the normal host, particularly in the case of meningitis. The compromised host is different than the normal host in the distribution of pathogens, which is determined by the nature of the host defense defect. In compromised hosts, differential diagnostic possibilities are more extensive and the likelihood of noninfectious explanations for CNS symptomatology is greater. (ABSTRACT TRUNCATED)     

Diagnosis and treatment of diabetic foot infections.

Prompt clinical diagnosis and timely treatment are the hallmarks of the proper care of diabetic patients with foot infections. The importance of careful clinical foot examination cannot be overemphasized. When infection is suspected, effort should be made to search for deeper infections, especially osteomyelitis. Numerous imaging techniques are available, but their cost-effectiveness has not been fully determined. Radiography of the foot is less sensitive but can provide useful information at a lower cost. Radio-isotope studies have not yielded consistent results, but the newer techniques deserve attention. Microbiological diagnosis should be attempted using only deep tissue culture, including bone biopsy. The primary aim of treatment of the infected foot is to restore ambulation. Timely surgical intervention and appropriate antimicrobial therapy can reduce the incidence of above-ankle amputation and reduce the length of hospital stay.     

Conservative management of osteomyelitis in the feet of diabetic patients

Experience of conservative management of osteomyelitis in a specialized, multidisciplinary, diabetic foot clinic was reviewed. The records of all patients attending the clinic over a 10-year period were examined retrospectively, and 22 patients with overt osteomyelitis were identified. Median age was 66 (31–87) years. In 12 cases the bone infection was a complication of a pre-existing ulcer; the most prevalent organism cultured from swabs was Staphylococcus aureus. The main site of infection was the first toe. The total duration of antibiotic treatment was 12 weeks (median, range 5–72), and clindamycin was the most commonly used oral agent. Four patients did not respond to initial conservative therapy and proceeded to amputation, while 1 patient responded clinically but had a recurrence of osteomyelitis at the same site 6 years later. In the remaining 17 patients resolution of osteomyelitis was achieved with conservative management over a median period of follow-up of 27 (range 5–73) months. The success of conservative therapy with prolonged courses of oral antibiotics challenges conventional advice that excision of infected bone is essential in the management of osteomyelitis affecting the foot in diabetes. © 1997 by John Wiley & Sons, Ltd.