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Diabetic Exam

Leg Colour



  • Inspection of the colour of the lower limbs in diabetics can suggest the presence of arterial insufficiency, venous insufficiency or infection.

Lower Limb Erythema

    • Look For

    • Redness - unilateral, bilateral, localised or diffuse.
    • Causes of Lower Limb Erythema

    • CellulitisTender, red, swollen, warm calf ± site of injury
    • Skin conditionsMacules, papules, patches or plaques - localised / diffuse
    • Lipodermatosclerosis (fibrosis of subcutaneous fat)Inverted bowling pin appearance with erythema / induration
    • LymphoedemaNon-pitting oedema, usually bilateral
    • Deep venous thrombosisRed, swollen, tender calf
    • Superficial ThrombophlebitisTender area with erythema tracking along the course of a superficial vein
    • Venous insufficiencyHyperpigmentation that may be associated with varicose veins or oedema.
    • Dependent rubor(peripheral arterial disease)Dusky-red discolouration when the leg is elevated above the heart

Pallor of the Lower Limb

    • Look For

    • Loss of colour in one or both lower limbs.
    • Causes of Pallor of the Lower Limb

    • Anaemia
    • Peripheral arterial disease
    • Compartment syndrome
    • Low cardiac output, due to cardiac disease
    • Peripheral shutdown, due to increased sympathetic activity

Lower Limb Cyanosis

    • Look For

    • Blue discolouration of the lower limb.
    • Significance

    • Nail bed cyanosis is a type of peripheral cyanosis, or high levels of deoxygenated haemoglobin (hypoxaemia) in the peripheries. Always look for central cyanosis (under the tongue) when this is present.
    • Causes of Lower Limb Cyanosis

    • Central Cyanosis

    • High altitude
    • Obstructive lung disease, pulmonary oedema, pneumonia, pulmonary embolism
    • Congenital heart disease
    • Methaemoglobinaemia / sulfhaemoglobinaemia / carboxyhaemoglobinaemia
    • Peripheral Cyanosis

    • As for central cyanosis
    • Reduced cardiac output
    • Vasoconstriction
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