Lower leg ulcers are common among the elderly and up to 75 per cent are the consequence of venous insufficiency. However, as healthcare practitioners, we must all remain alert to the possibility of ulcers caused by arterial insufficiency because the sequelae, if missed, can be serious and even life-threatening.
How does ulcer formation differ?
Venous insufficiency causes congestion (or blood pooling) as a result of poor venous return. This is often a direct result of faulty valves within leg veins but could also be caused by intravenous obstructions or thromboses. In either case, as blood continues to pool, the resulting venous hypertension leads to fluid leakage out of the veins, resulting in oedema, skin deterioration and ulcer formation.
In contrast, arterial insufficiency is most often caused by atherosclerosis, resulting in oxygen deprivation or starvation of the tissues, leading to cell death and ulceration. Below are some observable differences.
ULCERS: Shallow, irregularly shaped; Between knees and ankles; Proximal to the medial malleolus
Oedema: Edematous legs
SKIN: Temp: Feels normal to touch; May be dry and flaky
PULSE: Pedal pulse normal
NAILS: Normal colouration
PAIN: Severe, worsens when legs are elevated
ULCERS: Round, may increase in size and depth; Lower 1/3 of the leg, may extend to toes; Present on the medial malleolus
Oedema: No oedema
SKIN: Temp: Feels cool to touch; May look shiny, dry and hairless
PULSE: Pedal pulse faint or absent
NAILS: Toenails may be yellowish
While compression therapy is the gold standard of treatment for ulcers that are venous in origin, ulcers caused by a blocked artery demand that the blockage be cleared in order to restore a healthy blood supply. Otherwise, gangrene, sepsis and amputation are all possible “worst case” scenarios.
Of Interest, Pyoderma Gangrenosum (PG) is known as “The Great Impostor”
Often described as elusive and difficult to diagnose, PG can manifest in chronic non-healing wounds. And there’s a very interesting case described by Contreras-Ruiz et al. under the title
Delayed diagnosis of pyoderma gangrenosum, wherein the authors describe a woman with a five-year history of a painful and enlarging leg ulcer originally diagnosed as venous. The wound had been surgically debrided and managed with saline-soaked gauze and compression therapy, but the authors began to suspect PG.
Note: Although PG is categorized among the inflammatory dermatoses, and is non-infectious, it often evolves in the setting of systemic illness; rheumatologic, gastrointestinal, renal etc. But PG is also known for its propensity for lower leg ulceration.
Back to the case study…A biopsy confirmed PG, and treatment included oral corticosteroids with topical 0.01% tacrolimus twice daily. The wound was covered with non-adhesive gauze and compression wrapping. After four weeks, the wound had improved noticeably and pain medications to manage wound pain were discontinued. The wound was completely healed after four months.
Main message from the authors?
The presence or absence of PG must be ascertained in all patients who present with a history of painful lower leg ulcers and PG risk factors such as rheumatoid arthritis, diabetes, inflammatory bowel disease, haematological conditions etc.