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Diabetic foot infections: Trouble afoot

Everyone knows diabetes predisposes to so many pathologies. Perhaps one of the more substantial sources of morbidity and mortality are foot infections. The greatest risk factor for diabetic foot infections (DFIs) is neuropathy, followed by peripheral vascular disease. Other contributing factors include autonomic neuropathy which decreases sweating, resulting in dry skin with entryways for bacteria. Concomitant peripheral arterial disease impairs blood flow to the extremities. The greatest risk for neuropathy is poorly controlled hyperglycemia. Patients are slow to recognize ulcers and subsequent infections due to decreased sensation in their lower extremities and minor trauma usually goes…

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Articles of Interest

Diabetic Foot Infections: Toe to Toe

Dr. Oehler begins by introducing the concept of a multidisciplinary team as essential to the management of these patients. He then describes the current epidemiology of diabetes and diabetic foot ulcers. He discusses Charcot arthropathy and how it occurs. Annual diabetic foot exams are also crucial to these patients, and Dr. Oehler reviews proper techniques and what to ask/examine. Some of the newer hypotheses about the importance of biofilms to the creation and persistence of diabetic foot wounds are presented.

Complications of Cellulitis in Diabetic Foot Infections

Severe infections should be treated intravenously with broad-spectrum antibiotics (e.g., imipenem/cilastatin), new fluoroquinolones (levofloxacin, ciprofloxacin), or third- or fourth-generation cephalosporins (ceftazidime, cefuroxime) and beta-lactam/beta-lactamase inhibitors (ampicillin/sulbactam, piperacillin/tazobactam). Patients in whom MRSA is suspected should be given a regimen that includes vancomycin or linezolid.

Diabetic Foot Infections: The Diagnostic Challenges

Diabetic foot infections (DFIs) are severe complications of long-standing diabetes, and they represent a diagnostic challenge, since the differentiation between osteomyelitis (OM), soft tissue infection (STI), and Charcot’s osteoarthropathy is very difficult to achieve. Nevertheless, such differential diagnosis is mandatory in order to plan the most appropriate treatment for the patient. The isolation of the pathogen from bone or soft tissues is still the gold standard for diagnosis; however, it would be desirable to have a non-invasive test that is able to detect, localize, and evaluate the extent of the infection with high accuracy.

Diagnosis and Treatment of Diabetic Foot Infections

The major predisposing factor to these infections is foot ulceration, which is usually related to peripheral neuropathy. Peripheral vascular disease and various immunological disturbances play a secondary role.

Fungal infection of the diabetic foot: The often ignored complication

Fungal infections of the foot in people with diabetes should not be ignored. They potentially have a role in the pathogenesis of ulceration; the literature suggests a high risk of secondary bacterial infection. Treatment should be initiated early to prevent spread, and preventative measures should be used to avoid infection and re-infection. Treatment must involve careful consideration of the person’s comorbidities and other medications.

Maggots are making a comeback in modern medicine

The larvae of the greenbottle blowfly (Lucilia sericata) feast on the bacteria and dead tissue in chronic wounds, cleaning out the wound and giving it more of a chance to heal. This is an ancient therapy, used since Biblical times, but fell out of favour with the invention of antibiotics. However, the rise of drug-resistant bacteria, combined with skyrocketing rates of chronic wounds from diabetes, has led to a resurgence of interest in using creepy-crawlies as treatment, usually referred to these days as maggot debridement therapy or larval therapy.

Necrotizing diabetic foot infection: A limb-threatening emergency

Necrotizing infections are among the most serious of such infections. Soft tissue necrotizing infection or necrotizing fasciitis is an infection involving any soft tissue layers associated with necrotizing changes and causing significant tissue destruction. When infection involves the lower limbs of diabetic patients, it is sometimes called wet gangrene; the term ‘necrotizing infection’ is however more adequate. The frequency of necrotizing infection in the diabetic population is not well known.

The microbiology of diabetic foot infections: a meta-analysis

The aetiology of DFUs typically reflects trauma superimposed upon peripheral neuropathy and ischaemia. Such diabetic foot ulcers commonly become sources of intransigent infection, whereupon they may be termed diabetic foot infections (DFIs). Although initially superficial, DFIs can become complicated by osteomyelitis. Management of DFIs is limited to wound care, antibiotics and amputation. These infections can be difficult to treat and, despite the administration of multiple rounds of antibiotics, prospects of clinical resolution of infection can still be poor and repeated courses of antibiotics risks selecting for antimicrobial resistance.

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StatPearls

Treating diabetic foot infections is not easy as the blood flow is compromised and the antibiotics usually cannot reach the diseased area. In many patients with diabetes mellitus, a foot infection progresses and the cure can take a lot longer compared to a nondiabetic.