Approach to non-healing wounds: Clinical sciences

A non-healing wound refers to a chronic skin and soft tissue wound that fails to heal within the normal healing time frame, which is 4 to 6 weeks. In the majority of cases, there is an underlying condition or an infection that prevents normal healing. These factors often lead to the loss of normal skin and soft tissue anatomy and function.

In general, non-healing wounds are divided into two main categories: ulcers, which include pressure, neuropathic, venous, and arterial ones; and other non-ulcer related chronic wounds like postoperative wound complications, neoplastic or radiation-induced skin lesions, and infectious or inflammatory wounds.

Alright, when a patient presents with a non-healing wound, your first step is to obtain a focused history and physical exam. On history, patients typically have underlying chronic medical conditions such as diabetes or peripheral arterial disease known to prevent proper wound healing by causing inadequate nutritional status or poor blood supply. They might report first noticing a small wound that progressed to a larger or deeper one over the course of weeks to months. In this case, consider ulcers.

Okay, let’s start with pressure ulcers. These ulcers form when prolonged pressure decreases the blood flow to an area of skin and its underlying soft tissue. Typically, patients have a history of immobility, like being bed- or wheelchair-bound, and poor nutrition. Additionally, they might have multiple comorbidities such as stroke or paralysis. Patients who are hospitalized or reside in nursing homes are at a greater risk of developing pressure ulcers.

On exam, you might see partial or complete skin loss with areas of dark ischemic discoloration or necrosis over bony prominences like the sacrum. Sometimes you might even see the underlying fat, muscle, or bone exposed. With these findings, you can diagnose pressure ulcers.

Here’s a clinical pearl! Although imaging is not needed to make a diagnosis, an MRI is often obtained to evaluate for osteomyelitis if there is exposed bone in the wound bed.

Alright, let's move on to neuropathic ulcers. This type of ulcer occurs in patients with peripheral neuropathy, often from diabetes. Physical exam typically reveals a deep painless “punched out” ulcer with surrounding callus around pressure points, such as plantar metatarsal heads of the feet. Additionally, patients often have reduced sensation on monofilament testing around the ulcer. In this case, the diagnosis is a neuropathic ulcer.

Here’s another clinical pearl! The management of neuropathic ulcers involves treating the wound and the underlying disease. Consider checking the patient’s HbA1c to make sure their diabetes is under control to prevent further progression of the neuropathic ulcer. Additionally, obtain an ankle-brachial index, or ABI, to rule out peripheral arterial disease. Once this is excluded, treatment consists of wound care and reduction of pressure around the wound with appropriate footwear and orthotics.

Okay, next let’s talk about venous ulcers. These patients often have a history of venous insufficiency, and report dull aching pain and swelling of the legs that improves with elevation. They might also have a history of smoking, prolonged standing, or deep vein thrombosis in the affected leg. On physical exam, ulcers are shallow with irregular borders surrounded by edematous and firm skin with reddish-brown hyperpigmentation. They are typically located at the medial malleolus.

Additionally, patients might have visible dilated and tortuous superficial veins along the same leg above the ulcer. In this situation, consider a venous stasis ulcer and obtain a venous duplex ultrasound. Venous reflux on ultrasound means that venous valves are incompetent, which causes increased venous pressure in the legs. With this finding, you can diagnose venous ulcers.

Alright, our final type of ulcer is an arterial ulcer. Patients usually report claudication and/or rest pain of the affected extremity and have a history of peripheral arterial disease, atherosclerosis, or smoking. On physical exam, you might see a punched-out, pale, gray, or yellow ulcer with a dry base often located at the distal ends of digits like the toes.

Additionally, the peripheral pulse proximal to the ulcer might be reduced or absent, and the limb might be cold to touch with shiny skin and hair loss. With these findings, consider arterial ulcers and obtain an ABI to evaluate for arterial insufficiency. An ABI of less than 0.9 confirms peripheral arterial disease.

TIme for a clinical pearl! Patients with peripheral arterial disease often have other systemic vascular conditions related to atherosclerosis like carotid artery stenosis or coronary artery disease, which should be considered during surgical planning.

Okay, now that we’re done with ulcers, let’s talk about different findings. History often reveals external forces of injury like trauma or surgery, or other underlying diseases like cancer or inflammatory conditions. These conditions can contribute to the patient’s inadequate nutritional status or impaired blood circulation impeding their wound healing. Patients report these wounds starting as minor ones that progress or do not get better. In this situation, consider other chronic non-healing wounds that are not related to ulcers.