A patient has an ulcer above the medial malleolus. It aches, and the ache improves when the leg is elevated. The surrounding skin is brown and thickened. What type of ulcer is it, and what is the treatment? ANSWER: a VENOUS ulcer. The treatment is COMPRESSION. THE FEATURES ALL POINT ONE WAY: SITE above the ankle, MEDIAL side DEPTH shallow, sloping edge PAIN aches, RELIEVED BY ELEVATION SKIN brown staining, oedema, thickening — chronic venous hypertension BUT BEFORE COMPRESSING: ASSESS THE ARTERIAL SUPPLY. Feel the pulses and look at the foot. WHY: compression on a limb with arterial disease reduces an already inadequate inflow and can cause NECROSIS and limb loss. An elderly arteriopath can have venous skin changes AND arterial disease at the same time — the ulcer that looks venous may be both.

An ulcer on the toe is deep with a punched-out edge and is PAINFUL, worse when the patient elevates the leg. What type is it, and why does elevation make it worse? ANSWER: an ARTERIAL ulcer. WHY ELEVATION WORSENS IT: gravity was ASSISTING perfusion. Raising the leg removes that assistance, so an already marginal blood supply falls further and the pain increases. This is the exact OPPOSITE of a venous ulcer, where elevation helps by reducing venous pressure. OTHER ARTERIAL FEATURES: toes, heel and pressure points; cold foot; diminished or absent pulses; hairless skin; slow capillary refill. THE ONE QUESTION THAT SORTS THE THREE ULCER TYPES: Does it hurt, and does elevation help or worsen it? Aches, better elevated → VENOUS Hurts, worse elevated → ARTERIAL Does not hurt at all → NEUROPATHIC

A patient reports leg pain that wakes him at night and is relieved by hanging the leg out of bed. He has been sleeping in a chair. What does this indicate? ANSWER: REST PAIN — arterial supply no longer meets even RESTING demand. WHY HANGING THE LEG HELPS: gravity assists perfusion to a limb whose arterial inflow is critically reduced. WHERE THIS SITS ON THE SPECTRUM: CLAUDICATION pain on walking, relieved by rest — supply meets resting demand but not exertion REST PAIN supply insufficient even at rest TISSUE LOSS ulceration or gangrene REST PAIN plus TISSUE LOSS = CRITICAL LIMB ISCHAEMIA → urgent vascular referral. Without restored flow the limb will be lost. THE DETAIL WORTH NOTICING: "sleeping in a chair" is easily recorded as insomnia or breathlessness. Ask WHY they moved out of bed.

A limb is painful, pale, pulseless and cold. The patient now reports numbness and cannot move the toes. What is the significance of the last two findings? ANSWER: they are LATE features. Nerve and muscle are already being damaged, so this limb is further along and needs FASTER action. THE SIX FEATURES: Pain · Pallor · Pulselessness · Perishing cold · PARAESTHESIA · PARALYSIS. The order matters more than the list — the last two indicate established tissue injury rather than threatened tissue. ACTION: REFER IMMEDIATELY. Do NOT wait for imaging to confirm what the examination has already shown. Muscle tolerates ischaemia for only a few hours. EMBOLUS OR THROMBOSIS? SUDDEN onset, atrial fibrillation, normal other leg, no claudication → EMBOLUS Gradual onset, known peripheral arterial disease, claudication in both legs → THROMBOSIS on existing disease A mottled limb that does NOT blanch on pressure is generally beyond salvage.

Why must the feet of every diabetic patient be inspected even when they report no problem? ANSWER: because NEUROPATHY means they cannot feel the problem — so the absence of a complaint means nothing. THE DIABETIC FOOT COMBINES THREE PROBLEMS, each concealing the others: NEUROPATHY the injury is never felt — a stone in the shoe, a tight strap, a burn from a heater. Nothing hurts, so nothing stops. ISCHAEMIA so the injury cannot heal. Arterial disease in diabetes is more distal and more diffuse, and harder to bypass. INFECTION spreads with few signs. Deep infection and OSTEOMYELITIS can exist beneath a small, quiet-looking ulcer, and the usual inflammatory response may be muted. INSPECT BETWEEN THE TOES AND UNDER THE HEEL. This is one of the few examinations where finding nothing is genuinely reassuring, and not performing it is genuinely negligent.

Why are ankle-brachial pressure index values not quoted in this chapter? ANSWER: because the measurement is UNRELIABLE IN CALCIFIED VESSELS. 1. The index depends on being able to compress the artery with a cuff. 2. In calcified vessels, the artery does not compress normally, so the reading is FALSELY HIGH. 3. Calcification is common in DIABETES and CHRONIC KIDNEY DISEASE. 4. That is exactly the population at highest risk of arterial ulcers and critical ischaemia. So a normal-looking index in the patient who most needs the arterial supply assessed may be the least trustworthy. THRESHOLDS ALSO DIFFER between sources. WHAT TO DO: use the clinical findings — pulses, temperature, skin, pain on elevation — and refer for formal arterial assessment where there is doubt, rather than relying on a single number.