Diabetic foot wounds are challenging to manage and can be costly to the person with diabetes and the healthcare system. The colonisation of a diabetic foot wound can lead to infection, a frequent precursor to amputation. Here, the authors report the use of topical negative pressure therapy, in conjunction with a silver foam dressing, to reduce bacterial burden in colonised chronic diabetic foot ulcer and prevent progression to infection.

Foot ulceration is a serious complication of diabetes with a reported incidence of 1-3.6% (Ramsey et al, 1999; Boulton, 2008) and a prevalence of up to 25% (Singh et al, 2005). Diabetic foot ulceration is known to result in more hospital admissions than any other diabetes-related complication (Lavery et al, 2006). Infection is a common complication of diabetic foot ulcers and frequently a precipitating factor in amputation (Lipsky et al, 2004). Prevention of infection is, therefore, a clinical priority during wound healing.

The usual approach to diabetic foot ulcer management includes wound debridement, infection control and offloading with regular review. One technology used to assist wound closure and reduce bioburden is topical negative pressure (TNP) therapy. TNP therapy provides negative pressure at the wound surface, thereby lowering oxygen tension, stimulating angiogenesis and removing wound exudate (Banwell and Musgrave, 2004).

Identification and quantification of invasive pathogens is key in the effective management of infection, and thus access to microbiological processing is of paramount importance (Lipsky, 2008). Deep tissue samples are preferred, and repeated sampling is important to verify isolates and provide targeted antimicrobial therapy (Pellizzer et al, 2001). To avoid the overuse of antimicrobial agents, it is important to clinically differentiate between soft tissue infection and colonisation (Nelson et al, 2006). Among people with diabetes, making such diagnoses can be difficult due to the dampening of inflammatory responses (Nelson et al, 2006).

In this article, the authors present the case of Mr X, a 48-year-old man with type 2 diabetes who presented with a non-healing neuroischaemic ulcer to his lateral malleolus. The ulcer was colonised but not infected. A silver foam dressing was used in conjunction with TNP therapy in an effort to avoid infection and achieve wound closure.