As the incidence of diabetes has steadily increased over the last several decades throughout the United States, diabetic foot infections have also become increasingly common. As many as one in four people with diabetes will have a foot ulcer in their lifetime, and these wounds can easily become infected. If left unchecked, they can spread and may ultimately require amputation of the toe, foot, or part of the leg. Nearly 80% of all nontraumatic amputations occur in people with diabetes, 85% of which begin with a foot ulcer.
“Lower extremity amputation severely affects quality of life in people with diabetes because it reduces independence and mobility,” says Warren S. Joseph, DPM, FIDSA. “Furthermore, about 50% of patients who have foot amputations die within 5 years, which ranks as a worse mortality rate than for most cancers.” However, about half of lower extremity amputations that are not caused by trauma can be prevented through proper care of foot infections. Preventing amputations is vital. In most cases, these infections can be prevented or cured when properly managed.
Recommendations for Diabetic Foot Infections
In a 2012 issue of Clinical Infectious Diseases, the Infectious Diseases Society of America (IDSA) published a clinical practice guideline for diagnosing and treating diabetic foot infections. The guideline addresses 10 common questions with evidencebased answers that experts have determined are most likely to help healthcare providers treating these infections. The guideline is a revision and update of IDSA’s 2004 recommendations for managing diabetic foot infections.
With regard to diagnosis, the guideline recommends that infections in foot wounds be defined clinically by the presence of inflammation or purulence, and then classified by severity (Table 1). “The first step is to determine if the wound is infected,” says Dr. Joseph, who was on the IDSA panel that created the guidelines. “An infection is likely if there are at least two of the following signs: redness, warmth, tenderness, pain, or swelling. After classifying the severity of the infection, the guideline then provides evidence-based strategies to optimize treatment.” When foot sores are infected, imaging the foot is usually necessary to determine if the bone is infected. The guidelines recommend performing a culture of the wound to determine the bacteria causing the infection but stress the importance of appropriately obtaining those cultures. This information can be used to guide clinicians on whom antibiotics should be provided for treatment.
Addressing Antibiotic Use for Infection
The guideline emphasizes the importance of rapid and appropriate therapy for treating infected wounds on the feet. Therapy can include surgical debridement of dead tissue, appropriate antibiotic therapy, and removing pressure on the wound and improving blood flow to the infected area, when necessary. Importantly, many diabetic foot ulcers are not clinically infected and therefore should not be treated with antibiotics. People with clinical evidence of infection, however, require antibiotic therapy. Those with a severe infection should be hospitalized immediately.
“About 50% of patients who have foot amputations die within 5 years, which ranks as a worse mortality rate than for most cancers.”
“Many patients with foot infections initially receive only antibiotic therapy,” Dr. Joseph says. “In many cases, providing antibiotics alone will be insufficient in the absence of proper wound care and surgical interventions. Unfortunately, clinicians often overprescribe or inappropriately prescribe antibiotics for diabetic foot wounds. This approach is ineffective and can lead to antibiotic resistance.” Before considering antibiotic therapy, it is important to balance the clinical evidence of infection and its severity with other risks, such as risk factors for MRSA and Pseudomonas infection (Table 2). When antibiotics are necessary, they should be discontinued when the infection is gone, even if the wound has not completely healed.
Involve Others in Care
Since treating diabetic foot infections can be complicated, the guidelines recommend involving a multidisciplinary care team that can assess and address various aspects of the problem. “Data have shown that many foot infections are treated improperly,” says Dr. Joseph. “Getting assistance from other providers—including infectious disease specialists, podiatrists, surgeons, and orthopedists—can best address the complicated care of these infections.” For providers in rural areas, the guidelines note that telemedicine may facilitate consults with appropriate experts.
The IDSA guideline is intended to support decision-making processes based on individual circumstances rather than take the place of a physician’s judgment, Dr. Joseph says. “The guidelines will be revisited as more data emerge. Potential performance measures on outcomes of treatment and processes of management are also being explored. In the meantime, it’s hoped that free access to these recommendations will improve the diagnosis and treatment of diabetic foot infections and perhaps alleviate their burden over time.”