Haematology 699 Superficial thrombophlebitis or deep vein thrombosis? Superficial thrombophlebitis (phlebitis) and deep vein thrombosis (DVT) are both common conditions and they share some clinical features and risk factors. It is important to differentiate between the two disorders because they are managed differently. In part one of this two-part article, the clinical features and the differential diagnosis of phlebitis and DVT are examined. Part two will examine the management options for each condition. Dr Nabil Aly Consultant physician, DME, University Hospital Aintree, Liverpool, Lower Lane, Liverpool L9 7AL email [email protected] Superficial thrombophlebitis to obtain valid estimates of its affects individuals older than 40 is a common inflammatory- frequency. The exact incidence years and the male-to-female thrombotic process that may of DVT is also unknown because ratio is 1.2:1, indicating that occur spontaneously or as a most studies are limited by the males have a higher risk of DVT complication of medical or inherent inaccuracy of the clinical than females.2,3 surgical interventions. It has diagnosis of peripheral venous the same pathophysiology disorders. More importantly, and pathogenesis as deep vein most DVTs are occult and usually Pathophysiology thrombosis (DVT) and shares resolve spontaneously without most of its risk factors. complication; therefore, some Microscopic thrombosis is a Although uncommon, a DVTs are never diagnosed. normal part of the dynamic superficial thrombophlebitis can The existing data probably balance of haemostasis. In 1846, sometimes progress through underestimate the true incidence the German pathologist Virchow perforating veins to adjacent deep of DVT, but the incidence of recognised that if this dynamic veins. Therefore, not surprisingly, venous thrombosis (including balance was altered by venous the incidence of associated DVT) in hospitalised patients is stasis, abnormal coagulability, or DVT and pulmonary embolism considerably higher and varies vessel wall injuries, microthrombi (PE) in people with superficial from 20 to 70%.2 could propagate to form thrombophlebitis is relatively high.1 Age is not an independent macroscopic thrombi. In the However, ruling out a DVT in risk factor for superficial absence of a triggering event, this clinical setting is difficult and thrombophlebitis, but the neither venous stasis nor abnormal often further testing is required incidence of other recognised risk coagulability alone causes to evaluate for a DVT. No single factors increases with age. This clinically important thrombosis, physical finding or combination of leads to an overall increased risk but vascular endothelial injury symptoms and signs is sufficiently with increasing age.1 does reliably cause thrombus accurate to establish the diagnosis. The overall incidence of formation. The initiating injury venous thromboembolic diseases triggers an inflammatory response is increasing as the population that results in immediate platelet Epidemiology ages. It rises markedly in persons adhesion at the site of injury. 60 years and older, and may be as Further platelet aggregation is Superficial thrombophlebitis is high as 900 cases per 100,000 by mediated by thromboxane A2 and so common that it is difficult the age of 85 years.3 DVT usually by thrombin. www.gerimed.co.uk December 2010| Midlife and Beyond | GM 700 Haematology Platelet aggregation due to However, not all venous thrombi venous thromboembolic disease, thromboxane A2 is inhibited pose equal embolic risk and and up to 30% of patients reversibly by non-steroidal anti- isolated calf vein thrombi carry a with DVT or PE may have a inflammatory drugs (NSAIDs) limited risk of PE.2 thrombophilia. 5,6 Evaluation and irreversibly by aspirin, for thrombophilias should be but these drugs do not affect considered in patients younger thrombin-mediated platelet Aetiology than 55 years with an idiopathic aggregation. Therefore, for this episode of DVT, patients with reason, neither treatment is very Risk factors for superficial recurrent thrombosis, and effective for preventing or treating thrombophlebitis include a patients with a family history of venous thrombosis. history of local trauma, prior thromboembolism.3 The diagnosis The formation, propagation, similar episodes, varicose veins of DVT is confirmed in only 20- and dissolution of venous (veins that have become enlarged 30% of emergency admissions thrombi represent a balance and tortuous without phlebitis), with clinically suspected DVT, between thrombogenesis and the prolonged travel, hormone use, and a clinical study evaluating body’s protective mechanisms tobacco use or family history of 1102 acutely ill, immobilised (specifically, the circulating blood coagulopathies. However, admitted general medical inhibitors of coagulation the absence of identifiable risk patients, found four factors to be and the fibrinolytic system). factors has no prognostic value. independently associated with The development of venous The most important clinically an increased risk for venous thrombosis is best understood as identifiable risk factors are thromboembolism (VTE): the activation of coagulation in a prior history of superficial presence of an acute infectious areas of reduced blood flow, which thrombophlebitis and/or DVT. disease, age >75 years, cancer, explains why the most successful The risk of DVT in a patient and history of prior VTE. Most of prophylactic regimens are with superficial thrombophlebitis these factors were asymptomatic anticoagulation and minimisation is remote. One case-series and diagnosed by venography of of venous stasis. study found that it occurred both lower extremities.7 very occasionally if the DVT thrombophlebitis extended above DVT of the lower extremity the knee.4 Clinical features usually begins in the deep veins The clinical evaluation of of the calf around the valve cusps patients with suspected DVT Patients with superficial or within the soleal plexus. A is via an assessment of risk thrombophlebitis often describe minority of cases arise primarily in factors. Specific risk factors for a history of a gradual onset of the iliofemoral system as a result venous thromboembolic disease localised tenderness, followed of direct vessel wall injury, such as (mainly DVT and/or pulmonary by the appearance of an area of from hip surgery or intravenous embolism; PE) include increasing erythema along the path of a catheters. The vast majority age, prolonged immobility, superficial vein. Patients may also of calf vein thrombi dissolve surgery, trauma, malignancy, complain of a hard, painful “knot” completely without therapy and pregnancy, oestrogenic in a previous varicose vein. approximately 20% propagate medications and hormone The classic signs of DVT, proximally, which usually occurs therapy, congestive heart failure, including Homans’ sign (pain on before embolisation.2 The process hyperhomocysteinemia, and passive dorsiflexion of the foot), of adherence and organisation of diseases that alter blood viscosity oedema, tenderness, and warmth, a venous thrombus does not begin (eg, polycythemia, sickle-cell are difficult to ignore, but they are until 5-10 days after thrombus disease, and multiple myeloma), of low predictive value and can formation. Until this process has and inherited thrombophilias. occur in other conditions such as been established fully, the non- At least one established risk musculoskeletal injury, cellulitis, adherent disorganised thrombus factor is present in approximately and venous insufficiency.6 Many may propagate and/or embolise. 75% of patients who develop DVT patients are asymptomatic; GM | Midlife and Beyond | December 2010 www.gerimed.co.uk Haematology 701 Box : Clinical features of DVT and thrombophlebitis Superficial thrombophlebitis DVT Inspection Inspection Erythema, oedema, and pain are common Oedema is principally unilateral Swelling may result from acute venous Erythema and local pain may occur obstruction (as in DVT) or venous reflux Venous distension and prominence of the Normal veins are distended visibly at the foot, subcutaneous veins ankle, and occasionally in the popliteal fossa Palpation Palpation Tenderness, if present, is usually confined to the Superficial thrombophlebitis is characterised by calf muscles or along the course of the deep veins the finding of a palpable, indurated, cordlike, in the medial thigh tender, subcutaneous venous segment Homans’ sign: discomfort in the calf muscles Palpation of a painful or tender area may reveal a on forced dorsiflexion of the foot with the knee firm, thickened, thrombosed vein straight and it is neither sensitive nor specific: it Palpable thrombosed vessels are virtually always is present in less than 1/3 of DVT patients, but is superficial found in more than 50% of patients without DVT however, the history may include: this test, the propagation of a without coexisting varicose unilateral oedema, non-specific palpable pulse wave suggests that veins and with no other obvious leg pain in about 50% and a fluid-filled vessel with open or aetiology (eg, intravenous tenderness in 75%, which could incompetent valves connects the catheters, intravenous drug abuse, also be found in 50% of patients two locations. and soft tissue injury) had an without objectively confirmed associated DVT.4 DVT.6 The value of various The pain and tenderness Differential diagnosis diagnostic tests and imaging associated with DVT does studies in predicting the not usually correlate with the Superficial