Cause of lower limb ulcer :- venous/ arterial or neuropathic?

Hello!

Q. Today, in our OPD ,a 45 year old diabetic Male, farmer by profession  presented with an ulcer on left lateral malleolus .

He had a  history of oedema in lower limb a/w itching 2years back. 6 months back he got an ulcer on left lateral malleolus which is not healing since then.

On examination:-
Pigmentation of skin ,eczema lipodermatosclerosis ,atrophied Blanche are present  and dilated veins on the medial aspect of left lower limb.

My  question is how to differentiate whether the ulcer has arised due to neuropathy ,Venous stasis  or obliteration of artery .

Why this doubt has arised?
Because Venous ulcer are commonly found at the lower third of the leg usually on the medial side and even on the foot.

Ans.
(I) To rule out neuropathy ,

1.Ask whether he feel the ground and peeble while walking barefoot
2.Test for the pain sensation ,whether it is intact or not.

(II) Venous ulcer have characterstic finding. History is utmost important. They are shallow and flat. The edge is sloping and purple blue colour. The floor :- appears pink due to presence of granulation tissue. If it is a chronic ulcer there is more white fibrous tissue. Most important is A FAINT BLUE RIM of advancing epithelium is seen at the margin.

(III) To check for arterial obliteration

1.Feel the dorsal pedis pulsation.
2.Ask for claudication also.

Conclusion :- It was Venous ulcer.

Then why did it has appeared in the lateral side ? On inspection dilated veins  were found in the medial side?

Before answering the above question. Let us ask one more thing why is it most common on medial side?

There are more perforating veins on medial side means more pressure in that area. But that doesn't means lateral side is  spared .It also have some raised pressure .The only thing precipitated this was " Trauma".Due to more itching in lateral side,he traumatized that area .It was initially minor non healing area  which has gradually increased in the size.

Coincidentally,I have found this great article .

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1127371/

Hope you have got an edge.
Take care.:)

-Upasana Y.