Foot Infections: Five Early Signs You Need to Know
Infections and their management
(Infectious Symptoms and Management)
An infection refers to the situation where a wound from a diabetic foot ulcer (DFU) in diabetic foot patients is invaded and proliferated by bacteria or fungi1. It is the most common cause of hospitalization among diabetes-related complications and the primary cause of lower limb amputation2. Approximately half of the ulcer wounds will become infected, about 20% of which will require hospitalization for treatment3. Therefore, it is particularly important to detect early and prevent the worsening of the infection.
Causes of Infection
Foot infections in DFU patients are often caused by the breach of the skin's protective barrier, allowing exposure to bacteria from the external environment; however, the presence of bacteria on the surface and surrounding area of the ulcer wound is a very common and normal occurrence, as bacteria do not necessarily immediately invade the wound tissue of the patient2. If, for some reason, bacteria have the opportunity to invade the wound tissue and proliferate, causing an inflammatory response, this is then termed a wound infection2.
Factors that contribute to infection for DFU patients include2：
- Having chronic hyperglycemia
- Having deep, long-standing, recurrent or trauma-induced ulcer wounds
- The presence of immune dysfunction related to diabetes or concurrent chronic kidney failure
Consequences of Infection
The inflammatory response from the infection causes redness, swelling, heat, and pain in the wound and surrounding tissue, followed by tissue damage. Initially, the infection is usually limited to the surface but may continue to spread to the subcutaneous tissue, involving tissues such as tendons, muscles, and bones. The resulting inflammatory response can lead to ischemic necrosis of the tissue, potentially endangering the limb of the patient, and in severe cases, can cause systemic symptoms such as fever and metabolic disorder, affecting the patient's survival. If not promptly detected and appropriately treated, the progression of an infection can be quite rapid2.
Signs of Early Infection
According to the classification system proposed by the International Working Group on the Diabetic Foot and the Infectious Diseases Society of America (IWGDF/IDSA), the presence of at least two of the following symptoms may indicate a mild infection (Classification 2: Mild), and patients should seek medical attention promptly to prevent the condition from worsening to the point where hospitalization is required2：
- Redness around the wound of 0.5 to 2 cm
- Local swelling of the wound
- Increased local warmth
- Local tenderness or pain
- Purulent discharge
Basic Management Strategies for Infection
After detecting an infection, antibiotics should be used as directed professionally, which may include topical, oral, etc., for at least one week, in conjunction with comprehensive care and wound care. Antibiotics should not be used for the prevention of infection if no infection is found in the wound. Instead, interventions to prevent infection should start with changes in lifestyle2.
Want to learn about the treatment options for diabetic foot ulcers?
"DFU Treatment Guide: The Three-Step Approach of Wound Care, Offloading, and Education"
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Reference：
- van Netten JJ et al. Diabetes Metab Res Rev. 2023;e3654.
- Senneville É et al. Diabetes Metab Res Rev. 2023;e3687.
- Armstrong DG et al. JAMA. 2023;330(1):62-75.