A 64-year-old woman is evaluated in a nursing home for a foot ulcer. Three months ago, she had a cerebrovascular accident and now has residual hemiparesis with contractures. Her other medical problems include hypertension, diabetes mellitus, hypercholesterolemia, coronary artery disease, and mild dementia. Temperature is 37.2 C (98.9 F), blood pressure is 142/63 mm Hg, and pulse is 62/min. She is alert and oriented to person but not to time or place. There are no new focal neurologic deficits. Skin examination shows ulcerations on the left foot with mild erythema as shown in the image below.
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Which of the following is the primary cause of this patient's skin ulcers?
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This patient has typical pressure (decubitus) ulcers. Pressure ulcers are most common over bony prominences, such as the sacrum, ischial tuberosities, malleoli, heels, and 1st or 5th metatarsal head. Constant, unrelieved pressure causes necrosis of overlying skin and muscle as blood flow to the soft tissues is impeded. Risk factors include impaired mobility, malnutrition, abnormal mental status (eg, dementia), decreased skin perfusion, and reduced sensation.
Initial management of pressure ulcers includes local wound care, repositioning of the patient to reduce pressure, pain control, and nutritional support. Shallow ulcers can be managed with occlusive or semipermeable dressings to maintain a moist wound environment. Full-thickness wounds may require more complex dressings and surgical intervention for debridement or closure.
(Choice A) Arterial ulcers are due to insufficient blood supply that leads to tissue necrosis. They usually occur in the most distal parts of the body where blood flow is lowest, such as the tips of the toes.
(Choice B) Signs of bacterial infection include fever, blanching erythema, purulence, and foul odor. Although all pressure ulcers are colonized with bacteria, only clinically evident infections should be treated.
(Choice C) Diabetic foot ulcers result from chronic unnoticed trauma due to peripheral neuropathy and poor wound healing due to microvascular insufficiency. They often occur in association with Charcot deformity and are most common on the soles of the feet under the metatarsal heads and at the tops of the toes.
(Choice E) Venous stasis ulcers usually occur in the setting of chronic lower-extremity edema and stasis dermatitis. They are most common at the pretibial area or above the medial malleolus.
Educational objective:
Prolonged pressure over a bony prominence can cause ischemic necrosis of overlying tissues, leading to a pressure (decubitus) ulcer. Risk factors include impaired mobility, malnutrition, abnormal mental status, decreased skin perfusion, and reduced sensation.