Summary
Leg ulcers are especially common in older people (over the age of 60-65). They have a quite a significant social and economic impact in terms of medical care, young active people stopping work, and a poorer quality of life. They are mainly due to impaired circulation in the veins (70% of cases), arteries (20%), or mixed causes (10%) i.e. both veins and arteries being affected. There is a long list of “rare” causes of leg ulcers.
Hypertensive leg ulcers (or Martorell’s ulcers, named for the Spanish cardiologist who first described them) are among the less common types of leg ulcer, but this does not mean that they are rare. There is no consensus in terms of the criteria for diagnosis and this has led to underestimation of how common hypertensive leg ulcers are. Nonetheless, it is estimated that hypertensive leg ulcers account for 10% - 15% of leg ulceration seen in hospital admissions in dermatology wards. Hypertensive leg ulcers have traditionally been considered as the fourth most common cause of leg ulceration, after vascular causes (venous, arterial, and mixed).
The vast majority of cases of hypertensive leg ulcer develop in patients with a long history of arterial hypertension (HT), with 60% of cases affecting women. Hypertension is present in 95 - 100% of cases, while diabetes, mainly type II, is found in 40% of patients. However, in 5 - 10% of cases, diabetes appears to be the only cause of arteriolosclerosis, which is the underlying cause of Martorell’s ulcer, when patients do not have hypertension. It affects patients across quite a broad age range, from 40 to 85 years old, although it usually affects those between the ages of 55 and 65. Yet an aging population and improvements in the management of hypertension are gradually leading to older patients being affected with hypertensive leg ulcer. It is no longer unusual to see patients aged 75 or older with this condition.
Hypertensive leg ulcer is characteristically an extremely painful superficial leg ulcer that spreads slowly and is necrotic (made up of black plaques) and purplish. It typically develops on the outer side of the back of the leg. Pain is a major feature of this ulcer, and it is far in excess of what would be expected in view of the wound itself. This pain is not relieved by rest or by elevating the legs and it causes loss of sleep. An injury to the local area is considered to be a factor that can trigger this condition, but only 50% of patients mention this. Hypertensive leg ulcers develop exclusively below the knee and above the tops of the feet. They can progress in two stages, with the first lesion stabilising while a second one develops in another site or on the other leg. The ulcers vary in size from 2 - 242 cm2 (14). The time taken to heal varies, but hypertensive leg ulcers are broadly considered to undergo a long healing process. Healing may take over three months with topical treatments, and almost up to a year. This timeframe can be shortened if a skin graft is used. Amputation is only the outcome of very rare cases.
Impaired circulation in the veins or arteries is quite common in older patients. As hypertensive leg ulcer affects patients with a long history of HT, it is not uncommon for them to present associated peripheral arterial disease, although this must not be severe enough to explain the presence of the wound by itself if a diagnosis of hypertensive leg ulcer is to be made. This means that the possibility of peripheral arterial disease must always be explored during initial investigations, and this is especially important when the ulcer is hollowed out or follows an unusually long and chronic course.
The differential diagnoses include all other causes of leg ulcers. Doctors should always look for impaired circulation in the veins and arteries in these patients. The other differential diagnoses include all other causes of purpuric and necrotic lesions such as calciphylaxis, cutaneous vasculitis, cutaneous manifestations of thrombosis, cutaneous embolism, or other diseases such as pyoderma gangrenosum or ecthyma gangrenosum.
Hypertensive leg ulcers are usually resistant to conventional topical treatments and their management is overall a long and difficult process. It is important for the patient to be informed that hypertensive leg ulcers do progress in this particular way so that they avoid any waiting or high expectations.
The first important aspect of management is controlling pain. Given the extreme pain associated with hypertensive leg ulcers, controlling this makes local wound care easier and makes patients less apprehensive. Oral treatments include pain medications classed as step I and II by the World Health Organisation: paracetamol and codeine, alone or in combination. Assessing pain using a visual analogue scale several times a day means that the treatment can be evaluated in terms of how effective it is. Opiate patches, oral opiates, or opiate derivatives may be needed, sometimes as a medication to be used prior to local wound care taking place. Dosage will take into account the patient’s tolerance in terms of age and kidney function. Treatments to relieve neuropathic pain are often used in addition to other medicines (pregabalin, tricyclic antidepressants) because the pain associated with hypertensive leg ulcers is often partly caused by neuropathy. However, once again, these types of medication are limited in their usage because of side effects. By contrast, applying very strong topical corticosteroids (clobetasol propionate) for a short time (one week maximum) to the active purplish edges of the wound does lead to pain control.
A dressing will be chosen based on the clinical appearance of the ulcer. If painful debridement (removing dead wound tissue) is required, Emla cream or xylocaine gel must be applied between 30 minutes and 1 hour before the dressing. Hydrogel dressings will be applied for 48 hours over the dry necrotic plaques with mechanical debridement every day. Hydrocellular dressings will be applied over moderately exuding fibrous wounds while alginate dressings are used for highly exuding lesions. The debridement of fibrin and necrotic plaques will be carried out very carefully, and it will associate a topical treatment and mechanical debridement, or even surgical debridement under a local or general anaesthetic.
Skin grafts remain the best treatment available for managing hypertensive leg ulcers. There are various techniques available. A 6mm pinch graft can be carried out quickly (in around 20 minutes) at the patient’s bedside under local anaesthesia. This is a simple and inexpensive technique that rapidly relieves pain and the wound heals quickly. A thin mesh skin graft obtained using a dermatome is thought to be similarly effective. It is quite common to have to carry out several grafts in one patient. The average time taken before the wound heals is about one month after the skin graft. Although no treatment (surgical or otherwise) has been assessed in controlled studies into hypertensive leg ulcers, skin grafts remain the first line treatment.
It is crucial to control the patient’s hypertension. Non-selective beta-blockers should be avoided because they lead to blood vessel constriction and can cause a delay in wound healing. However, an intensive treatment for HT only does not guarantee that hypertensive leg ulcers will be cured.
1 - CONCLUSION
Hypertensive leg ulcer is a distinct entity characterised by the specific clinical signs of painful and spreading necrotic ulcers, arteriolosclerosis, and a history of HT. HT is the main factor, but not the only one, to cause this small vessel disease. Patients with hypertensive leg ulcer may present signs of impaired circulation in the veins, arteries, or both. To date, very few comparative studies of treatments have been undertaken. Management consists of pain relief, controlling HT, and mechanical or surgical debridement with skin grafting.
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