Leg Ulcers

Latest update 11/12/10

Acknowledgement - this chapter was written by Dr Brian Malcolm. Brian is a GP principal and trainer in Barnstaple, North Devon and an Associate Specialist in Dermatology

This chapter is set out as follows:

• Introduction
• Aetiology and pathogenesis
• Clinical Assessment
• Management
• Complications
• Who to refer

Introduction

• Leg ulcers are of huge socio-economic importance costing the NHS over one billion pounds per year
• A leg ulcer is not a diagnosis; it is a manifestation of an underlying disease process.  The concept should be of the patient with the leg ulcer
• There are in excess of 100,000 active venous ulcers in the UK at any one time
• The lifetime incidence of venous ulceration is 1%
• 80% of leg ulcers have treatment that is based in the community

Aetiology and pathogenesis

A working definition of a leg ulcer would be an area of epidermal discontinuity lasting an excess of four weeks

• 70 – 80 % of leg ulcers are venous
• 10 – 20 % are of mixed venous/arterial
• 10% are arterial

Venous Ulcers

• The pathogenesis of venous ulceration is not completely understood but is generally agreed to be the end result of a combination of chronic venous hypertension resulting from venous incompetence and calf muscle insufficiency evidenced by the tissue changes of induration, haemosiderin deposition, fibrosis and reticulate scarring (atrophie blanche) collectively known as lipodermatosclerosus

	Figure 1 - Champagne bottle leg resulting from chronic lipodermatosclerosis
	Figure 2 -Atrophie blanche White reticulate scarring very evident
	Figure 3 - Early venous leg ulcer (arrow) Associated with significant gravitational eczema
	Figure 4 - Venous leg ulcer The ulcer is granulating nicely at the base, which is a good sign

Clinical Assessment

History

• A full medical history needs to be obtained with particular respect to co-morbid pathologies
• The history must include medications, as drugs such as beta-blocker, steroids and non-steroidal anti-inflammatories (NSAIDs) can all adversely influence ulcer healing
• A history of allergy/sensitivity, for example, reaction to neomycin or lanolin is also important when the choice of appropriate dressings and topical agents is being considered

Examination

• Site
  • Almost 90% of venous ulcers originate in the ‘gaiter’ area of the lower leg, most commonly on the medial aspect
  • In contrast arterial ulcers commonly occur on both the dorsal and plantar aspects of the foot and toes

• Appearance / symptoms
  • The clinical changes of lipodermatosclerosus support a venous aetiology.  Venous ulcers are usually shallow, ragged and sloping with variable pain
  • In contrast, arterial ulcers often have a punched out ‘cliff edge’ appearance with significant levels of pain except when there is co-existent neuropathy, for example in diabetes mellitus.  There may also be signs of arterial compromise such as pallor, loss of hair, nail dystrophy, coldness and diminished capillary refill.  Pulses may be impalpable

Investigations

• Ankle brachial pressure index (ABPI) - a baseline doppler assessment competently carried out is mandatory with normal values ranging from 0.92-1.3. An ABPI less than 0.9 suggests arterial involvement and levels less than 0.5 indicate severe arterial disease
• Baseline bloods should include full blood count, plasma viscosity, U&E, blood sugar and thyroid function
• Swabs should only be carried out if clinically indicated and not taken as a routine

	Figure 5 - Chronic extensive venous ulceration
	Figure 6 - Neuropathic ulcer on diabetic foot The lesion has a punched out appearance suggestive of arterial insufficiency

Management

Patients will all forms of ulceration often have very significant co-morbidities such as cardiac failure, hypertension, peripheral vascular disease, diabetes mellitus and connective tissue disease that require a holistic approach if there is to be successful ulcer healing

• Provide a patient information leaflet

• Cornerstones of wound management:
  • Define and treat underlying causes
  • Strict control of factors affecting healing, for example oedema and infection
  • Appropriate dressings
  • Compression therapy where possible
  • Long-term maintenance of successful healing

• Dressings - do not heal wounds.  All dressings, however, have the common goal of achieving an optimal environment for wound healing, which is moist but not macerated, with an optimal ph and temperature, permeable to air, and free of infection, toxins, allergens and irritants. It is beholdent on doctors to achieve a basic understanding of the different categories of dressings in order to have an informed conversation with their nursing colleagues. The dressing types include:
  • Films e.g. Opsite ® - these are polyurethane membranes, waterproof, transparent, flexibile and permeable to gas and water vapour.  They are non-absorptive and thus not suitable for heavily exuding wounds
  • Foams e.g. Lyofoam ® - heat treated polyurethane, very absorbent and insulating. Suitable for a wide range of granulating wounds both flat and cavity
  • Hydrogels e.g. Intrasite ® - organic polymers with an increased water content, hydrating and absorbent and capable of absorbing large amounts of exudates
  • Alginates e.g. Kaltostat ® - derived from seaweed, very absorbent, hydrating and haemostatic. These can be used in moderate or heavily exuding wounds
  • Hydrocolloids e.g. Granuflex ®and Comfeel ® - polymers in fins suspension, absorbent and promote autolysis. Available in pastes, granules and wafers
  • Inert e.g. any dressings and gauze - secondary dressings with primarily protective role.  These provide an optimal environment for moist wound healing
  • Proteolytic e.g. Varidase ®  - their major indication is for use in the early healing of sloughy or infected wounds

• Compression thearpy:
  • Compression therapy plays a very important role in the management of venous leg ulcers
  • There is an array of multi-layer bandaging systems available that are wrapped from the toes/foot to below the knee
  • Compression techniques can only be used if doppler readings are satisfactory - readings less then 0.8 would contra-indicate any form of compression therapy except in expert hands and under special circumstances. Extra care has to be taken is patients with diabetes where spuriously high ABPI readings can occur as a result of calcification and incompressibility of the vessels
  • In the best hands 70% of venous ulcers can be healed in compression bandaging within three months

• Systemic Treatments:
  • Evidence regarding the various merits of low-dose aspirin and drugs such as Trental ® (Oxypentifylline) remain contradictory and confused

• Surgery - see below 'Who to refer'

Figure 7 - Dressings

Complications

• Infection
  • True pathogens such as beta-haemolytic strep have to be treated energetically with appropriate antibiotics

• Over-granulation
  • Can be treated both physically with traditional silver nitrate or with potent topical fluorinated steroids such as Dermovate ® cream

• Malignant change
  • Squamous cell carcinoma is a rare complication of chronic wounds (also known as Marjolin’s ulcer)
  • More commonly some chronic ‘ulcers’ are misdiagnosed and are indeed primary malignancies. It is important to de-crust persistent lesions in order to identify the possibility of underlying neoplasia
  • Any suspicious lesion should be referred urgently as a two-week wait to a dermatologist

• Eczema / cellulitis
  • Patients with skin problems of the lower legs are frequently misdiagnosed as having ‘bilateral cellulitis’ and are treated inappropriately with several weeks of systemic antibiotics
  • Cellulitis is very unlikely to be bilateral and most of these patients instead have a chronic superinfected eczema
  • These patients are systemically well and often have a symmetrical bilateral distribution of well-demarcated stable erythema on their legs. If there is doubt a CRP can be useful to exclude the diagnosis of cellulitis
  • Eczema can be improved with the use of an appropriate topical steroid e.g. Betnovate-C ® cream until symptoms improve. Patients must not be left on topical steroids indefinitely
  • If eczematous changes persist consider the possibility of a contact allergic dermatitis to one of the topical treatments / dressings - patch tests may be required

	Figure 8 - Crusted lesion on lower leg
	Figure 9 - Same patient as above Lesion de-crusted to reveal an underlying SCC
	Figure 10 - Contact allergic dermatitis
	Figure 11 - Contact dermatitis ten days after topical steroids

Who to refer

Referral must be considered for the following cases:

1. Venous ulcers failing to progress at 3 months or which have not healed by 12 months
2. All ulcers of an arterial or mixed aetiology - assessment needed for reconstructive surgical/radiological procedures
3. Failure to adequately control underlying pathologies
4. Suspected malignant change (2-week wait referral to dermatology)
5. Suspected cases of contact allergic dermatitis
6. Post-healing - consideration should be given to the referral for further investigations of venous leg ulcers to see if surgical intervention would reduce the risk of re-ulceration. Such a referral would depend on local resources, and is particularly relevant for young patients 

Most patients needing referral will be managed by community leg ulcer (tissue viability) clinics or dermatology departments. However patients in groups 2+6 should be referred to vascular surgeons

Leg ulcer clinics can be a fascinating source of diverse pathology! Here are just a few examples:

	Figure 12 - SCC of toe treated as an ulcer for 4 years
	Figure 13 - Artefactual ulcer The patient had done this to themselves
	Figure 14 - Leischmaniasis
	Figure 15 - Ulcerating necrobiosis lipoidica