Cutaneous Manifestations of Diabetes

Arun Chakrabarty, MD; Robert A. Norman, MD; Tania J. Phillips, MD, FRCPC


Wounds. 2002;14(8) 

In This Article

Diabetic Ulcers

Diabetic patients form the single largest group of nontraumatic amputations in the United States.[40] For the majority of diabetic patients, the initial condition that leads eventually to amputation begins with a skin ulcer (Figure 5). Diabetic foot ulcers are separated into two categories: ischemic and neuropathic ulcers.[40] Peripheral neuropathy plays a central role in nearly four-fifths of diabetic patients. The most common neuropathy is a mixed distal motor and sensory neuropathy.[4,41] In the majority of cases, ulceration occurs as a consequence of the loss of protective sensation. The combination of motor and sensory neuropathy along with mechanical factors plays a role in the pathogenesis of neuropathic ulcers.[4,42] Clinical signs of paresthesias with loss of temperature and pain sensation along with disturbances in sweating are prevalent in neuropathic diabetic ulcers. The pathogenesis of ischemic ulcers involves diabetic atherosclerotic disease. The ischemic patient will present with disproportionately excruciating pain associated with a superficial ulcer, while the neuropathic patient is unaware of a large, deep ulcer. The ischemic patients will often elicit a history of intermittent claudication, foot pain on leg elevation, and pain relieved with resting.[40]

Diabetic neuropathic ulcer of the plantar foot. Peripheral neuropathy leading to loss of sensation is an early warning sign.

Prevention of foot ulcers is critical. Clinicians should routinely examine the feet of diabetic patients. A nylon monofilament test provides a method of early determination for the loss of peripheral sensation and identifies patients at risk for ulceration. Education in foot care, proper footwear, avoidance of burns and trauma, and close medical follow up are steps needed for the prevention of diabetic ulcers.[40] Glycemic control will diminish the progression of peripheral neuropathy, a key factor in the development of ulcers. Smoking cessation must be emphasized. Patient compliance along with physician intervention are the mainstays of the prevention strategy of diabetic ulcers.

Treatment of diabetic ulcers becomes necessary once preventive measures have failed. Many diabetic ulcers fail to heal because patients continue to put weight on their affected lower extremities. Approximately 90 percent of ulcers can be treated by relieving weight from the ulcerated area, treatment of infections with systemic antibiotics, and arterial perfusion restoration.[43] A common mistake is the use of wet-to-dry dressings on a clean ulcer bed.[40] The removal of the dry dressing interrupts the healing process of re-epithelialization. The preservation of a wet saline dressing maintains a moist wound environment. New adjunctive therapies, such as becaplermin gel (recombinant platelet-derived growth factor), show modest benefit in improving granulation tissue and wound repair.[44] The role of growth factors and cytokines in the process of wound healing is an area of ongoing investigation. Bioengineered skin equivalents, such as Apligraf® (Novartis Pharmaceutical Inc., East Hanover, New Jersey) and Dermagraft® (Smith & Nephew Inc., Largo, Florida), promote more rapid healing.[45] These innovative therapies are not substitute for basic management of diabetic ulcers, such as adequate offloading, treatment of infections, and debridement.[40,44] The decision to perform vascular surgery depends on the severity of the vascular impairment, the surgical risks, and rehabilitation potential. The therapeutic goal of the treatment of diabetic ulcers is the eventual healing and avoidance of amputation, thereby improving function and quality of life.