Differential diagnosis

Think about other causes of unilateral leg swelling. Common causes include ^a

• cellulitis
• muscle injury
• superficial thrombosis

• chronic oedema or venous insufficiency 
• pelvic tumours compressing lymphatic or venous drainage 
• a ruptured Baker's cyst 

Why?

DVT and cellulitis are the commonest causes of unilateral leg swelling in emergency departments

Differential diagnosis of unilateral leg swelling a	%
DVT	16% to 30%
cellulitis	6% to 9%
muscular injury	6% to 7%
superficial thrombosis	5% to 7%
ruptured Baker's cyst	2% to 6%
chronic oedema	3%
chronic venous insufficiency	3%
post-operative swelling	3%
arthritis	2%
pelvic tumour	1%