Ulcer in diabetes

Diabetic ulcers are one example of neuropathic ulcers.

• annual incidence of foot ulceration among diabetic patients with peripheral neuropathy is reported to be between 5.0 and 7.5% (1)

Peripheral neuropathy causes ulceration through its effects on the sensory, motor and autonomic nerves:

• loss of sensation due to sensory neuropathy makes patients vulnerable to physical, chemical and thermal trauma
  • loss of sensation is a major factor in nearly all diabetic foot ulcers
    • it is associated with a seven-fold increase in risk of ulceration
• foot deformities caused by motor neuropathy (such as hammer toes and claw foot) may lead to abnormal pressures over bony prominences
• dry skin, associated with autonomic neuropathy results in fissures, cracking and callus (1,2)

They always occur on the foot, usually on the plantar aspect under the metatarsal heads or on the plantar aspects of the toes (3).

• typically a diabetic ulcer is deep, painless, and infected and has a 'punched out' appearance
• these ulcers are known as 'perforating ulcers'

Note that infection may spread quickly and may lead to extensive limb-threatening necrosis and septicaemia.

Reference:

• (1) Boulton AJ, Kirsner RS, Vileikyte L. Clinical practice. Neuropathic diabetic foot ulcers. N Engl J Med. 2004;351(1):48-55.
• (2) International Best Practice Guidelines: Wound Management in Diabetic Foot Ulcers. Wounds International, 2013
• (3) Edmonds ME, Foster AVM. Diabetic foot ulcers. BMJ : British Medical Journal. 2006;332(7538):407-410