Article

Diabetic foot ulcer or pressure ulcer?

That is the question

Peter Vowden, Kathryn Vowden

This article was first published in The establishment of a correct diagnosis links care to established guidelines and
The Diabetic Foot Journal (2015;
18: 62–6). Copyright rests with underpins all subsequent therapeutic activity. Problems can arise when definitions
SB Communications Group. of disease overlap, as is the case with diabetic foot ulceration and pressure ulcers on
Citation: Vowden P, Vowden K
the foot occurring in people with diabetes. In such cases, clinicians must ensure that
(2016) Diabetic foot ulcer or patients receive a care bundle that recognises both the wound causation (pressure and
pressure ulcer? That is the question.
Diabetic Foot Canada 4: 26–29
shear) and the underlying pathology (diabetic neuropathy, potential foot architecture
disruption and ischaemia). All patients with diabetes who have foot ulceration,
Article points irrespective of wound aetiology should, therefore, be seen by the multidisciplinary
1. Confusion exists when
diabetic foot team. Care can then be optimised to include appropriate assessments,
naming (diagnosing) and
treating pressure-related foot including assessment of peripheral perfusion, correct offloading, appropriate diabetic
ulceration in people with
diabetes, particularly when
management, and general foot and skin care.

W
ulceration occurs on the heel.
hat’s in a name? That which mechanism by which the damage occurred. The
2. Diagnosis can and does affect
subsequent assessments we call a rose by any other name EPUAP definition goes on to state: “A number
and management and would smell as sweet. of contributing or confounding factors are also
this could potentially
 Romeo and Juliet (II, ii, 1-2) associated with pressure ulcers; the significance
compromise outcome.
of these factors is yet to be elucidated.” This
3. All people with diabetes and
foot ulceration, irrespective Unlike in a Shakespearean play, where a name is indicates the complexity of pressure ulceration
of wound aetiology, should seen as an artificial and meaningless convention, and highlights the gaps in our knowledge both
benefit from multidisciplinary the whole basis of managing a patient’s illness is to in accurately identifying patients’ risk and
foot team input.
establish a diagnosis or name for the illness. Once confirming ulcer aetiology.
a healthcare professional has named a problem, This definition of pressure ulceration includes
a treatment strategy – often laid out in specific pressure damage that occurs at the end of life,
Key words
guidelines – follows. The name of an ulcer is, sometimes referred to as “Kennedy ulcers”
- Care pathways
therefore, key to its subsequent management. (Schank, 2009), and also includes bandage trauma
- Diabetic foot ulcer
- Pressure ulcer or compression bandage damage, ulceration from
What is a pressure ulcer? devices such as oxygen masks or nasogastric tubes,
According to the European Pressure Ulcer urinary or other catheters, and pressure and shear
Authors
Advisory Panel (EPUAP) guidelines (EPUAP and damage from plaster casts or footwear.
Peter Vowden is Consultant
Vascular Surgeon, Bradford
Nation Pressure Ulcer Advisory Panel, 2014), a Most pressure ulcer prevalence studies (Barczak
Teaching Hospitals NHS pressure ulcer is defined as: “A localized injury et al, 1997; Clark et al, 2004; Vangilder et al, 2008;
Foundation Trust and Visiting to the skin and or underlying tissue usually over Vowden and Vowden, 2009a) identify the heel area
Honorary Professor of Wound
a bony prominence, as a result of pressure, or as the second most frequent location for a pressure
Healing Research, University of
Bradford, Bradford, UK. pressure in combination with shear.” Although ulcer, the most prevalent being the sacrum. The heel
Kathryn Vowden is a Nurse intended to be specific, this definition is wide accounts for between 23% and 28% of all pressure
Consultant, Bradford Teaching
reaching. It includes skin and deep tissue damage ulcers (Barczak et al, 1997; Clark et al, 2004;
Hospitals NHS Foundation
Trust and University of caused by pressure and/or shear, irrespective of the Vangilder et al, 2008; Vowden and Vowden, 2009a;
Bradford, Bradford, UK underlying medical condition of the patient or the 2009d) and is the most frequent site for pressure

26 Diabetic Foot Canada Volume 4 No 1 2016

 Diabetic foot ulcer or pressure ulcer? That is the question

ulceration in specific patient sub-groups, namely the and exposed tissue type — but should still activate “Overlap between
critically ill, older people and people with diabetes. a care pathway that is in line with the National definitions causes
Salcido et al (2011) state that the heel is the most Institute for Health and Care Excellence (NICE)
problems in wound
common area for deep tissue injury. Heel pressure guidance for pressure ulcer treatment (NICE,
ulcers are commonly found in both acute and 2014). This triggers risk and skin assessment, management pathways.”
long-term care facilities (Vangilder et al, 2008), are enhanced pressure relief and repositioning, but
frequently associated with delayed wound healing does not define a specific wound care strategy or
(Chipchase et al, 2005; Pickwell et al, 2013) and identify care-supporting investigations. However,
have a significant impact on patients’ quality of it does trigger prevalence and incident reporting,
life (Spilsbury et al, 2007). In a small retrospective investigation and analysis of the root cause.
study of 57 patients, Han and Ezquerro (2011) Identifying a wound as a diabetic foot ulcer may
reported that 42% (18 patients) of cases of heel result in a more detailed descriptive definition
pressure ulcers required amputation due to of the ulcer (Abbas et al, 2008) and should also
persistent infection or non-healing. result in a care pathway that follows the NICE
guidance (NICE, 2004; 2011). This will include
What is a diabetic foot ulcer? timely referral to the multidisciplinary diabetic
In the International Consensus on the Diabetic Foot foot care team where assessment of peripheral
(International Working Group on the Diabetic perfusion, neuropathic status, wound and callus
foot, 2007), a diabetic foot ulcer is defined as: debridement, and appropriate offloading with
“A full-thickness wound below the ankle in a general foot and nail care, as well as review of
diabetic patient, irrespective of duration. Skin diabetes management, would be performed.
necrosis and gangrene are also included in the Differing guidance for each wound type impacts
current system as ulcers”. This definition is on care provision. The Bradford Wound Care
similar to that of the EPUAP, all-inclusive and, Audit (Vowden and Vowden, 2009a; 2009b;
as such, any pressure ulcer on the foot of a person 2009c; 2009d; Vowden et al, 2009) highlighted
with diabetes is a diabetic foot ulcer – as is any the differences that occur in management when
traumatic wound, including a thermal or chemical foot ulceration among people with diabetes is
injury. It constitutes part of the ‘diabetic foot’ – classified as either a pressure ulcer or a diabetic
an interrelated group of complications, including foot ulcer (Figure 1a and b). People with diabetes
infection, ulceration, neuropathy and peripheral in the community setting classified as having
arterial disease that place the foot at risk of a heel pressure ulcer rather than a diabetic foot
amputation (Apelqvist, 2014). ulcer did not receive Doppler peripheral vascular
assessment, were not referred to the diabetic foot
Conflicting definitions service and did not, therefore, receive the benefits
This overlap between definitions causes problems of general foot care, offloading or orthotic referral.
in wound management pathways. Describing The mechanism of injury in both pressure
and classifying a wound helps guide clinicians’ ulceration and diabetic foot ulceration is often
subsequent management strategies and therapeutic similar (Figure 2) and this can understandably
requirements. For example, a leg wound described lead to problems in allocating a wound type to a
as a venous leg ulcer will receive compression specific wound.
therapy with appropriate venous investigations in Chadwick, commenting on a pressure ulcer
line with the NICE guidelines for venous disease prevalence survey in his local hospital that
(NICE, 2013). The Comprehensive Classification showed a larger than expected increase in the
System for Chronic Venous Disorders (Eklof et al, number of pressure ulcers, found that ward staff
2004) also allows a detailed description of both the were counting diabetic foot ulcers as pressure
ulcer and the underlying pathology. ulcers and concluded that staff were struggling
Identifying a wound as a pressure ulcer does to differentiate between pressure ulcers and
not offer such a detailed descriptive classification diabetic foot ulcers (Ousey et al, 2011). In the
system – limiting the classification to wound depth same article, Cook commented: “The real

Diabetic Foot Canada Volume 4 No 1 2016 27

Diabetic foot ulcer or pressure ulcer? That is the question

foot ulcers and pressure ulcers. Mendoza‑Mari

(a) 35 et al (2013) demonstrated that in diabetic
Foot pressure ulcer
foot ulceration granulation tissue cells exhibit
Leg/foot ulcer
30 a molecular “imprinting” toward glucose
homeostasis failure.
25 Irrespective of the name applied to a foot
ulcer, any non-healing wound on the foot
Patients (n)

20 should trigger detailed assessment of the limb’s

peripheral perfusion. Reliance on palpable pulses
15 and a Doppler ankle–brachial pressure index
may not be sufficient. The concept of foot and
10 lower-leg angiosome (Wright and Fitridge, 2014)
demonstrates the importance of identifying
5 regional perfusion within the ulcerated area and,
whenever possible, restoring in-line pulsatile
0 perfusion to that region.
Podiatrist Podiatrist Neither
and specialist podiatrist nor
nurse specialist nurse Conclusion
Seen by When is a diabetic foot ulcer a pressure ulcer
and when should these ulcers be included
(b) 80
in pressure ulcer prevalence data? These are
No questions that many clinicians struggle with. The
70 Yes breadth of the definition of pressure ulceration
60
could be interpreted as including most diabetic
neuropathic and neuroischaemic foot ulcers as the
50 skin break, damage or ulceration is usually caused
by pressure and or shear.
Patients (n)

40
The authors’ view is that people with diabetes
30 with an ulcer or wound on the foot should
have the benefit of assessment by a specialist
20
multidisciplinary team and treatment pathways
10 established by the diabetic foot services,
irrespective of the name placed on the ulcer.
0
Foot ulcer Pressure ulcer – foot Patients with ulceration on the heel are, as a
group, most likely to be classified as having
pressure ulceration. These patients frequently
Figure 1. Differences in (a) the care pathway for foot pressure ulcer patients and (b) the struggle with impaired mobility and poor
vascular assessment pathway (Doppler ankle-brachial pressure index performed, yes or no) for healing and often fail to benefit from foot team
foot ulceration in people with diabetes depending on classification as a diabetic foot ulcer or intervention in their management.
pressure ulcer. Effective working and communications
issue is not whether the ‘label’ of the wound between healthcare professionals is essential
is correct, but that the patient receives the to allow implementation of complex care
most appropriate care through assessment and for people with foot ulceration. To optimise
correct referral within a prompt timeframe to a outcomes, all people with foot ulceration
‘specialist’ in that area.” should benefit from the input of a foot care
Although not directly relevant to a discussion team. Too many healthcare professionals focus
in relation to the naming of foot wounds among solely on the management of the wound and
people with diabetes, there may be histological ignore the integrated care benefits that follow
and transcriptional differences between diabetic multidisciplinary team involvement. n

28 Diabetic Foot Canada Volume 4 No 1 2016

 Diabetic foot ulcer or pressure ulcer? That is the question

Ulceration l PVD
l Central (cardiac/hypoxia
l Oedema
l Local ischaemia

Is
ch
ae
m
ia
l Support surface
l Diabetes l Medical equipment
N

l Anaesthesia l Foot wear

eu

l Cord/brain injury l Treatment

ro

l Peripheral neuropathy
pa

Pressure
th
y

and shear

l Immobility loading
l Mobility loading
l Anatomical abnormality
l Uncontrolled movement

Figure 2. Causes of non-traumatic heel and foot ulceration.

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