Lower Limb

Question 1

Unilateral ankle swelling DDx

Answer 1

Increased venous pressure: obstruction (DVT, tumour, LN), valvular incompetence (varicose veins, post-thrombotic syndrome), immobility
Increased capillary permeability: cellulitis, thrombophlebitis, ruptured Baker’s cyst
Lymphoedema: obstruction (lymphoma or mets, acutely due to streptococcal lymphangitis)

Question 2

Causes of oedema

Answer 2

Increased venous pressure
Decreased osmotic pressure (results in bilateral swelling)
Impaired lymphatic drainage (lymphoedema)
Increased capillary permeability

Question 3

Bilateral ankle swelling DDx

Answer 3

Increased venous pressure: CCF, cor pulmonale, valvular incompetence (varicose veins, post-thrombotic syndrome), immobility
Decreased oncotic pressure: GIT dysfunction (poor nutrition, malabsorption, protein-losing enteropathy), liver failure, renal failure (nephrotic syndrome)
Increased capillary permeability:
Lymphoedema: obstruction (lymphoma or mets, acutely due to streptococcal lymphangitis)

Question 4

Non-pitting oedema DDx

Answer 4

Lymphoedema

Pretibial myxoedema

Question 5

How can lymphoedema be distinguished from other causes of oedema?

Answer 5

Lymphoedema is non-pitting