Venous ulcers

Overview

Venous ulcers are the most common cause of chronic leg ulceration (~70-80% of all leg ulcers), caused by chronic venous insufficiency and sustained venous hypertension in the gaiter area.

Presentation

•Location - gaiter area (medial lower leg, above medial malleolus); rarely above the knee

•Ulcer appearance - shallow, irregular (sloping) edges; moist, fibrinous base

•Haemosiderin staining - brown-red skin discolouration from haemoglobin breakdown

•Lipodermatosclerosis - woody induration/fibrosis of lower leg; 'inverted champagne bottle' appearance

•Varicose eczema - itchy, scaly, weeping dermatitis around the ulcer

•Oedema - pitting oedema of ankle/lower leg, worsening through the day

•Pain - dull ache/heaviness, worse with dependency, relieved by elevation

•Atrophie blanche - pale, ivory-white atrophic plaques with telangiectasia at sites of previous ulceration

⚠️

Pain that worsens with elevation or severe rest pain should prompt consideration of an arterial component - always check ABPI before applying compression.

Investigations

•First-line (mandatory before compression): ABPI measurement

•ABPI >1.3 - vessel calcification (e.g. diabetes); ABPI unreliable, refer for specialist assessment

•ABPI 0.9-1.3 - normal; full compression safe

•ABPI 0.8-0.9 - borderline; full compression may still be appropriate with clinical review

•ABPI 0.6-0.8 - reduced compression only, under specialist guidance

•ABPI <0.6 - compression contraindicated; urgent vascular referral

•FBC - screen for anaemia (impairs healing); raised WCC if infection

•HbA1c/fasting glucose - diabetes impairs wound healing

•Wound swab - only if clinical signs of infection (erythema, warmth, purulent exudate, systemic features); do not swab routinely

🏆 Gold standard

•Duplex Doppler ultrasound - maps venous reflux, identifies valve incompetence; guides surgical decision-making

Differential Diagnosis

Venous vs arterial ulcer

Feature	Venous	Arterial
Location	Medial gaiter area, above medial malleolus	Pressure points, toes, heel, lateral malleolus
Ulcer edge	Shallow, irregular, sloping	Punched out
Base	Moist, fibrinous/granulating	Pale, necrotic, dry
Pain	Relieved by elevation	Worse with elevation/exercise
Surrounding skin	Haemosiderin staining, lipodermatosclerosis, varicose eczema	Pale, hairless, atrophic; absent pulses
ABPI	>0.8 (normal arterial supply)	<0.8

Management

🥇 First-line

•High compression bandaging (40 mmHg at the ankle) - multi-layer systems (e.g. four-layer bandaging) for uncomplicated venous ulcers with ABPI >0.8

•Compression hosiery (class 3, 25-35 mmHg) - once healed; for long-term prevention of recurrence

•Wound dressings - moist wound healing; non-adherent for low exudate; absorbent foam or alginate for high exudate

•Leg elevation - above hip level when resting; reduces oedema and venous pressure

•Second-line (confirmed infection): flucloxacillin 500 mg four times daily orally for 7 days; erythromycin or clarithromycin if penicillin allergic

•Varicose eczema: topical betamethasone valerate 0.1% cream (short-course) with emollients

•Refractory ulcers: pentoxifylline 400 mg three times daily orally - adjunct to compression

🥉 Third-line

•Surgical/endovenous intervention (endovenous thermal ablation, foam sclerotherapy, or surgical stripping) - reduces recurrence by correcting venous reflux

⚠️

Do not routinely prescribe antibiotics for colonised ulcers - all chronic wounds are colonised. Swab and treat only when there are local or systemic signs of infection.

Complications

•Cellulitis - most common; treat with flucloxacillin first-line; continue compression if tolerated

•Osteomyelitis - deep/longstanding ulcers; requires imaging and prolonged antibiotics or surgical debridement

•Marjolin's ulcer - malignant transformation (typically squamous cell carcinoma); suspect if raised/everted edges, bleeds easily, or fails to heal despite appropriate treatment; requires biopsy

•Recurrence - very common; rates up to 70%

Prognosis

•~50% heal within 6 months with appropriate compression therapy

•Recurrence rates up to 70% - long-term compression hosiery (class 2-3) is the most effective preventive intervention

•Poor prognostic factors: ulcer present >12 months, large size, low ABPI, impaired calf muscle pump, poor adherence to compression