The role of intravenous drug use in venous leg ulceration.

Abstract

V enous leg ulceration is thought to be a disease of old age and prevalence is around 1% of the adult population. However, as many as 46% of sufferers may develop their ulceration before the age of 50 (Mackenzie et al, 2003) and, increasingly, venous leg ulcers are occurring in younger people as a result of intravenous injecting. A recent study showed a high leg-ulcer prevalence of 15% in a sample of 200 people (aged under 44) who had injected drugs (Coull et al, 2014). The assessment process is important in the care of patients with leg ulceration. However, many leg ulcer assessments do not include a question about intravenous (IV) drug use, and IV drug use is rarely mentioned as a risk factor in literature about venous leg ulceration. Chronic venous disorders (CVDs) are classified in a staging system that ranges from no visible or palpable signs of venous disease through the signs of chronic venous insufficiency (CVI), varicose veins, oedema, skin changes, to ulceration as end-stage venous disease (EklOf et al, 2004). CVI commonly occurs in the sixth or seventh decade of life, but occurs in the third or fourth decade for people who inject drugs (PWID) (Pieper, 1996). It is important to recognise that prevalence is higher than expected, and be aware of key contributing factors that might cause leg ulceration in PWID, especially as ulceration may occur long after injecting has ceased (Pieper, 1996). Most significant is injecting in the femoral vein or the legs, and the presence of deep vein thrombosis (DVT). PWID may use the femoral vein as a site to inject into (groin injecting). This site can be used for many years and is associated with a lack of alternative access, easier technique, improved drug effect, and the fact that the site is easily hidden (Williams and Abbey, 2006). Femoral injecting is risky, with many reported problems. Repeated puncturing of the femoral vein may result in a noticeable dimples in the skin and eventually a sinus may form in some individuals (Maliphant and Scott, 2005). Swellings or aneurysms can occur in the groin area and there is a risk of inadvertent arterial injection, venous insufficiency, infection and pain (Gan et al, 2000; Senbajo et al, 2012). Scarring or thickening of the femoral vein can occur causing difficulty with injecting, such as needle breakage and a requirement to use longer, thicker needles. Swelling or thickening can lead to a narrowing of the lumen causing a slowing in venous blood flow, resultant back pressure and venous hypertension. Consequently, as the blood flow becomes sluggish, a DVT may form (MacKenzie et al, 2000). Injecting directly into the legs increases the likelihood of skin breakdown and ulceration. This is partly owing to the venous damage inflicted by repeated needle punctures and increased risk of infection and DVT in the lower legs (Pieper et al, 2009). DVT is a risk factor in the development of venous ulceration, and, although DVT is relatively common in PWID, there is a lack of awareness of the long-term consequences on the lower limb (Williams and Abbey, 2006). A clot in the leg, especially proximal to the knee, also increases the likelihood of post–thrombotic syndrome (PTS), which is characterised by signs of venous insufficiency with limb swelling, pain, skin changes, difficulty in walking and venous ulceration (Kahn and Ginsberg, 2004). PTS has been known about for many years (Linton, 1953) but little is known about the risk factors or why it occurs in some and not others. Despite this, it is possible that the PTS sequelae, including ulceration that follows DVT, could be prevented in up to 50% of sufferers by using compression hosiery (Prandoni et al, 2004). However, a study by Kahn et al (2014) contradicted earlier results and showed elastic compression stockings did not prevent PTS. Further trials are needed, but hosiery may offer symptomatic relief and would be advised for those with a proximal DVT at or above the popliteal vein (Arumugaswamy and Tran, 2014). Other guidelines suggest that those with PTS should wear compression hosiery constantly and forever, to minimise the extension of disease and venous ulcer formation (Robson et al, 2008). Compression can also have a dramatic effect on reducing pain (Ettridge, 2011). Health professionals caring for PWID should be aware of the high prevalence of leg ulceration in this group, and consider their role in the prevention of ulceration following DVT and in PTS. Early recognition of PTS may help reduce the prevalence of leg ulceration. Educating this group about the long-term consequences is also worthy of consideration. BJN