Identifying Skin Conditions Of Diabetic Patients

Many people with diabetes develop skin manifestations as a result of having the disease. In some instances, such skin problems may be the first sign that the patient has diabetes. Proper recognition is the key to successful treatment, but making the proper diagnosis can be difficult. Some conditions may have similar characteristics and presentations. With this in mind, test your diagnostic acumen with the following case.
A 64-year-old female with non-insulin-dependent diabetes mellitus came into the office with right and left leg ulcerations. The patient’s past medical history is significant for peripheral vascular disease, Charcot foot deformity, hypertension, pulmonary sarcoidosis and thyroid condition. She says the ulcerations just popped up a couple of weeks ago. The patient says the skin on her legs is itchy and it looked like a dull red area at first presentation. She reports no pain and admits that her blood sugar is not in very good control.

What Is The Differential Diagnosis?
1. Necrobiosis lipoidica diabeticorum
2. Diabetic neuropathic ulceration
3. Bullous pemphigoid
4. Venous stasis ulceration

A Closer Look At Possible Answers
1. Necrobiosis lipoidica diabeticorum (NLD) is the correct answer. Besides the common neuropathic and arterial type of ulcer, NLD can also occur in patients with diabetes. These ulcerations usually occur most often in women under the age of 40. These types of lesions typically occur over the front of the lower extremities and are oval and irregular in presentation. These ulcerations are reddish-brown plaques with central atrophy and translucent telangiectasias. NLD usually starts as a dull red raised area, but after a little while, you’ll see that the skin appears shiny with a violet border. Sometimes, NLD is itchy and painful.
A minor trauma usually precedes the development of these ulcerations. Between 60 to 70 percent of patients with NLD have diabetes, but only about .3 percent of diabetic patients are affected by NLD.

2. Diabetic neuropathic ulceration is not the correct answer. You’ll commonly see these ulcers on the plantar aspect of the foot, usually over the metatarsal heads and over a weightbearing area. Characteristically, diabetic neuropathic ulcers present with a rim of hyperkeratotic tissue and a pink granulating tissue bed, if there is no infection or osteomyelitis. Neuropathic ulcers are usually associated with surrounding callus and clinically have a punched-out appearance. These ulcers usually do not have large amounts of exudate and they are not painful.
Furthermore, you must remove pressure from these ulcers by employing inserts, special molded shoes or contact casting.
3. Bullous pemphigoid is not the correct answer as it is a chronic pruritic benign bullous skin eruption that primarily occurs in geriatric patients. Clinically, the development of tense bullae occurs on normal or erythematous skin areas. The initial symptom may be pruritus followed by the blisters. Both men and women are affected equally. This disease is considered to be an autoimmune disease. Antibodies directed towards the basement membrane zone of the epidermis are usually found in the skin and serum. It’s important to differentiate bullous pemphigoid from other conditions such as erythema multiforme, drug eruptions, pemphigus and linear Ig A disease.
You’ll usually see blisters of bullous pemphigoid on the areas of the body that flex or move (flexural areas). About one-third of the patients with bullous pemphigoid also develop blisters in the mouth. This disorder can occur in various forms, ranging from no symptoms to mild redness and irritation to multiple blisters. Bullous pemphigoid is characterized by patterns of exacerbations and remissions. The patient can be without symptoms for five or six years and then he or she may experience a flare-up. Treatment is primarily focused on relieving the symptoms and preventing infection.
4. Venous stasis ulceration is not the correct answer. You’ll usually see these types of ulcers on the medial aspect of the leg. Characteristically, these wounds present with similar characteristics such as edema, stasis pigmentation, dermatitis and ulceration. The venous stasis ulcer is primarily due to sequelae of chronic venous insufficiency. Patients with venous ulcers may have a history of deep vein thrombophlebitis and thrombosis. They may also have dilated superficial veins.

Diagnosis And Treatment
Necrobiosis lipoidica diabectorum (NLD) is a rare skin complication of diabetes that is due to small blood vessel diseases of the skin. It is a disease of unknown origin. Clinically, the affected skin appears as a reddish-brown border with a yellowish center. NLD typically presents as erythematous violaceous plaques on the anterior surfaces of the lower legs. These lesions are typically asymptomatic.
In some cases, the onset of this skin disease may precede the diagnosis of diabetes and so patients with this skin disorder should be screened for diabetes. Presently, there is not one effective treatment. While topical and intralesional steroids can arrest inflammation, be aware that these modalities will aggravate the diabetes.
Patients with diabetes are prone to foot ulcerations due to both neurologic and vascular complications. The presence of infection is an increased risk factor for the patient with diabetes and can worsen the ulceration and potentially lead to an amputation. Peripheral neuropathy can cause altered or complete loss of sensation in the foot and/or leg. Neuropathy causes a loss of sensation and it compromises the biomechanics of the foot.
A poorly fitted shoe in a patient with neuropathy can cause unnoticed injury that may ultimately result in ulcer formation. Similar to the feeling of a “fat lip” after a dentist’s anesthetic injection, the diabetic patient with advanced neuropathy loses the ability to feel any sharp or dull sensation. Any cuts or trauma to the foot can go completely unnoticed for days or weeks in a patient with neuropathy. It’s not uncommon to have a patient with neuropathy tell you that the ulcer “just appeared” when, in fact, the ulcer has been present for quite some time. There is no known cure for neuropathy but strict glucose control has been shown to slow its progression.
Charcot foot deformity occurs as a result of decreased sensation. Additionally, it is a complication of neuropathy and failure to recognize this process can lead to further complications, including amputation. A patient with advanced neuropathy is prone to tissue ischemia and necrosis, which may lead to plantar ulcerations. Also keep in mind that microfractures in the bones of the foot go unnoticed and untreated, resulting in disfigurement, chronic swelling and additional bony prominences.
Medical management for our diabetic patients is a team approach. This team consists of many medical professionals, including endocrinologists, vascular surgeons, podiatrists, infectious disease specialists, diabetic educators, primary care physicians and wound care specialists. Timely referrals to the appropriate discipline are critical for optimal treatment.

Dr. Fishman is Chairman of the Wound Care Institute in North Miami Beach, Fla.