PassFinals
Dermatology

Leg Ulcers

A leg ulcer is a wound below the knee that fails to heal, and its cause must be established before treatment: venous, arterial, diabetic/neuropathic, pressure, inflammatory, traumatic and malignant ulcers need different pathways.

In a nutshell

A leg ulcer is a non-healing wound whose cause must be established before treatment. Venous ulcers usually need trained compression after arterial assessment; arterial ulcers need vascular assessment and must not receive unsafe compression; diabetic or neuropathic foot ulcers need prompt foot-service referral and offloading. Treat only clinical infection, not colonisation, and refer red flags or non-healing atypical ulcers.

Classic presentation

An older patient has a shallow irregular medial gaiter-area ulcer with oedema, pigmentation and venous eczema; ABPI is adequate, so trained compression and wound care are indicated. A painful distal ulcer with absent pulses is an arterial emergency until assessed.

Key points

  • Classify the ulcer and document size, depth, site, pain, pulses, sensation, oedema and surrounding skin.
  • Measure ABPI or use an equivalent trained arterial assessment before strong compression.
  • Venous ulcer: compression is the main healing treatment when arterial supply is adequate.
  • Arterial or mixed ulcer: vascular referral and safe perfusion management take priority; do not apply strong compression blindly.
  • Diabetic foot ulcer: offload, assess infection and ischaemia, and use the multidisciplinary foot-care pathway.
  • Most ulcers are colonised, not infected; antibiotics require clinical signs such as spreading redness, warmth, increasing pain or fever.
  • Atypical, rapidly worsening, inflammatory or non-healing ulcers need specialist assessment and possible biopsy.

First-line investigation

Holistic lower-limb and ulcer assessment with arterial assessment before compression, plus targeted venous, diabetic, infection or biopsy investigations according to the pattern.

Management

Identify limb- or life-threatening disease

  • Escalate acute or chronic limb-threatening ischaemia, gangrene, sepsis, necrotising infection, osteomyelitis and high-risk diabetic foot ulceration urgently.8,7,6

Classify and measure before treatment

  • Complete a holistic leg and ulcer assessment, measure the wound, assess pulses and sensation, and obtain ABPI or equivalent arterial assessment before strong compression.3,5

Treat venous, arterial and diabetic causes differently

  • Use trained compression for venous disease with adequate arterial supply, vascular referral and no unsafe compression for arterial or mixed disease, and prompt offloading and foot-service care for diabetic or neuropathic ulcers.3,8,7,4

Optimise the wound and the person

  • Clean and dress appropriately, protect periwound skin, manage oedema and pain, encourage safe mobility and elevation, support nutrition and smoking cessation, and address concordance and underlying disease.3,4,9

Treat infection only when clinically present

  • Do not treat colonisation; use antibiotics for clinical infection, reassess worsening or non-response within 2 to 3 days, and refer sepsis, osteomyelitis, necrotising infection or spreading infection not responding to oral treatment.6,9

Measure healing and investigate failure

  • Review healing, pain, oedema, compression, infection, skin condition and cause; refer atypical or non-healing ulcers for vascular, dermatology, rheumatology, diabetes or biopsy assessment as appropriate.3,6,2

Exam traps

  • Do not apply compression before assessing arterial supply.
  • A high ABPI can be unreliable in diabetes or renal disease because of arterial calcification; seek specialist vascular assessment.
  • A positive wound swab does not prove infection and antibiotics do not promote healing of an uninfected ulcer.
  • Venous, arterial and neuropathic ulcers can coexist; do not force every ulcer into a single category.
  • Diabetic foot ulceration with fever, ischaemia, gangrene or deep infection is an urgent multidisciplinary problem.
  • A non-healing or atypical ulcer may be malignant or inflammatory and should not be managed indefinitely as a routine venous ulcer.

Illustrations

Chronic venous leg ulcerA clinical photograph of a chronic irregular venous leg ulcer with exudate, slough and granulation tissue, showing the surrounding venous skin changes and the importance of a full-limb assessment.Raimundo Pastor, Wikimedia Commons · CC-BY-SA-4.0

Key sources

  1. NICE CG168: Varicose veins: diagnosis and management (NICE vascular pathway for venous leg-ulcer definition, duplex assessment and treatment of significant venous reflux; last reviewed 4 February 2016 and accessed 4 August 2026.)Updated 4 Feb 2016
  2. NHS: Venous leg ulcer (Current NHS information on venous-ulcer presentation, specialist assessment, underlying causes and recurrence prevention; accessed 4 August 2026.)
  3. National Wound Care Strategy Programme: Leg Ulcer Recommendations (UK lower-limb wound-care recommendations embedded in the current NICE HTG758 supporting documentation, including holistic assessment, arterial assessment, compression thresholds, mixed disease referral and follow-up; accessed 4 August 2026.)Updated 27 Aug 2025
  4. NHS: Venous leg ulcer—treatment (Current NHS information on professional compression, dressings, elevation, exercise, infection and follow-up; accessed 4 August 2026.)
  5. Right Decisions NHS Scotland: Community venous leg-ulcer clinic standard operating procedure (UK NHS operational pathway for holistic assessment, ABPI interpretation, trained compression, referral and reassessment; accessed 4 August 2026.)
  6. NICE NG152: Leg ulcer infection: antimicrobial prescribing (NICE antimicrobial-prescribing pathway for clinical infection, sampling, reassessment, referral and antibiotic selection in adults with leg ulcer infection; published 11 February 2020 and accessed 4 August 2026.)Updated 1 Jan 2022
  7. NICE NG19: Diabetic foot problems: prevention and management (NICE diabetic-foot pathway for referral, offloading, wound care, infection, ischaemia, osteomyelitis and Charcot assessment; last reviewed 3 July 2025 and accessed 4 August 2026.)Updated 3 Jul 2025
  8. NICE CG147: Peripheral arterial disease: diagnosis and management (NICE peripheral-arterial-disease pathway for tissue loss, limb-threatening ischaemia, risk-factor management, imaging and vascular referral; updated 30 June 2020 and accessed 4 August 2026.)Updated 30 Jun 2020
  9. British National Formulary (BNF) (BNF online prescribing information for analgesia, antibiotics, wound-care products and comorbidity-specific treatment; current details must be checked at the point of care; accessed 4 August 2026.)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.