What are the key clinical features that differentiate arterial ulcers from venous ulcers in primary care?

Key clinical features differentiating arterial ulcers from venous ulcers in primary care:

• Location: Arterial ulcers typically occur on the toes, feet, or pressure points such as the lateral malleolus, whereas venous ulcers are usually found on the medial aspect of the lower leg, especially around the gaiter area (above the ankle and below the calf).
• Appearance: Arterial ulcers often have a punched-out, well-demarcated edge with a pale or necrotic base and minimal exudate. Venous ulcers tend to have irregular, shallow edges with granulation tissue and moderate to heavy exudate.
• Surrounding skin: Arterial ulcers are associated with signs of peripheral arterial disease such as cool, pale, or shiny skin, hair loss, and diminished or absent pulses. Venous ulcers are commonly accompanied by signs of chronic venous insufficiency including oedema, lipodermatosclerosis, venous eczema, and varicose veins.
• Pain: Arterial ulcers are often painful, especially at rest or when the leg is elevated. Venous ulcers usually cause aching or heaviness that improves with leg elevation.
• Other features: Venous ulcers often have associated leg swelling and pigmentation changes due to venous hypertension, whereas arterial ulcers may be accompanied by intermittent claudication or rest pain indicating ischaemia.

Assessment of arterial supply using ankle-brachial pressure index (ABPI) is essential before applying compression therapy for venous ulcers to exclude arterial insufficiency, as compression can worsen arterial ulcers ¹,²,⁵.