Case 33: Flat footed
A diabetic man is referred to you because of a non healing ulcer on the sole of his foot.
1. Describe the appearance of the ulcer and foot.
Classically described as a Charcot's foot there is aevidence of gross structural deformity in this foot with flattening of the plantar arch and abnormal weight bearing areas. There is a chronic ulcer with rolled edges overlying the base of the 5th metatarsal. The toes are clawed and no longer weight bearing. The skin of the foot and leg is dry and cracked.
2. What features can you see and deduce that predispose to development of this ulcer?
This is a neuropathic foot. The structural changes imply motor neuropathy with loss of the intrinsic muscles of the foot. The location of the ulcer suggests sensory neuropathy. The skin changes may be a result of peripheral arterial occlusive disease but may also be manifestations of autonomic neuopathy with resultant abnormalities in blood flow and sweating leading to dry, cracked skin prone to infection.
The most likely cause for this appearance in western society is longstanding diabetes mellitus. As such there is likely to be micro and macrovascular occlusive disease as well as defects in immune function that contribute to skin ulcer development, sepsis and delayed healing.