Diabetic foot ulcer – the importance of recognising and managing infection

A man in blue scrubs and a woman in a white coat look at a tablet together.

Diabetes affects about 422 million people worldwide, with steadily increasing numbers over the past few decades.¹ It affects the heart, eyes, kidneys, nerves, and blood vessels. Peripheral neuropathy and peripheral artery disease (PAD) are the leading causes of diabetic foot disease – one of the most severe complications of diabetes mellitus.²

Development of diabetic foot ulcers

Diabetic foot ulcers can have many causes. However, peripheral neuropathy and peripheral arterial disease (PAD) are among the most common risk factors.
Neuropathy impairs sensitivity, causing abnormal loading of the foot. This results in thickened skin, also called callus formation. Callus formation increases pressure on the underlying tissue, causing skin breakdown and ulceration.
PAD occurs in up to 50% of patients with diabetic foot ulcers and is mainly caused by atherosclerosis.² It impairs the blood flow and causes ischemia, which negatively affects wound healing.
The majority of diabetic foot ulcers either result solely from peripheral neuropathy (purely neuropathic) or a combination of neuropathy and ischemia caused by PAD (neuro-ischemic). Minor foot trauma or poorly fitting shoes can also cause ulcerations in diabetic patients.²

How diabetes affects wound healing

Limb ischemia due to peripheral artery disease increases the risk of a diabetic foot ulcer becoming infected and impairs the treatment outcome. The presence of clinically significant foot ischemia makes both diagnosis and treatment of infection considerably more difficult.³ Diabetic foot disease is the commonest cause of hospitalisation in people with diabetes and precedes more than 80% of diabetes-related amputations.⁷

Close-up of a foot with a stitched wound near the heel.

Infected diabetic foot ulcer after amputation

Signs of infected diabetic foot ulcers

The increasing prevalence of diabetes leads to a rising number of foot complications, including infections.⁵ The typical signs and symptoms of infection are often absent in patients with diabetes caused by peripheral neuropathy and peripheral artery disease.³ Every patient with diabetes and an active diabetic foot ulcer should be assessed by a multidisciplinary team, including diabetes and wound nurses, general practitioner, diabetologist, and vascular consultant, among others.¹⁰

Diabetic foot infection is identified if at least two of the following signs are present:³

Local swelling or induration
Erythema of more than 0.5 cm around the wound (refers also to any part of the foot, not just of a wound or an ulcer)
Local tenderness or pain
Local increased warmth
Purulent discharge

Patients with a diabetic foot ulcer are at risk of osteomyelitis.

EXTRA TIP:

In people with dark skin tones be aware of the signs and symptoms of infection that do not solely rely on redness ⁴

Other causes of an inflammatory process of the skin—such as trauma, gout, acute Charcot neuro-osteoarthropathy, fracture, thrombosis, or venous stasis—must be ruled out for the diagnosis of an infected diabetic foot ulcer.³ Patients with diabetes are prone to spreading infections to fascia, tendons, muscles, joints and bones, which are also fostered by the anatomy of the foot. Severely infected diabetic foot ulcers and moderately infected diabetic foot ulcers that are complex or associated with key relevant morbidities require immediate hospitalisation for urgent systemic antibiotic therapy, including surgical intervention in many cases. The typical signs of systemic infection—for example fever, chills, elevated leucocytes, or significant metabolic disturbances—are often absent in diabetic patients. Therefore, an experienced team of healthcare professionals is required to rule out this potentially life-threatening complication.³

Take-home messages

Even minor foot trauma or poorly fitting shoes can cause foot ulcers in patients with diabetes.
The presence of peripheral neuropathy and peripheral artery disease can alter and mask the typical infection signs in patients with diabetes.
Local infection in diabetic foot ulcers can present with local swelling, erythema, tenderness or pain, increased warmth, or purulent discharge.
Identifying infection in people with dark skin tones by investigating signs and symptoms that do not reply on redness.
Patients with diabetes are prone to spreading infections, which are also fostered by the anatomy of the foot. In case of suspected infection, an experienced team of healthcare professionals is required to rule out this potentially life-threatening complication.
Early detection of infection and early referral or consultation with specialists are essential.
The close collaboration of wounds specialists and clinicians is required to manage locally infected diabetic foot ulcers.
Proper care for locally infected diabetic foot ulcers requires a good wound assessment, wound management with cleansing, debridement and infection management.
Dressings with a physical mode of action, such as Cutimed Sorbact, support infection management and reduce bioburden in wounds.
Bring awareness to patients and relatives on appropriate foot ulcer self-care and how to recognise and report signs and symptoms of infection.
There are evidence based guidelines on offloading interventions to promote healing of foot ulcers in individuals with diabetes¹¹

Disclaimer

*This article is intended to be used as an information guide to be considered when the organisation makes clinical decisions and does not constitute medical advice. For detailed device information, including indications for use, contraindications, effects, precautions, and warnings, please consult the product’s Instructions for Use (IFU) before use. In case of doubt please consult a healthcare professional.

Infection management with Cutimed^® Sorbact^®⁸

Explore how Cutimed Sorbact designed with Sorbact Technology removes bacteria through a purely physical mode of action, without releasing active substances⁹. Smart technology that makes a big impact.