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Paper text:
although often life - threatening , the uncommon vascular infections are often clinically unsuspected and underdiagnosed .
septic thrombophlebitis represents a very rare condition , most usually reported to involve the dural sinuses , the internal jugular vein , the portal vein ( during abdominal inflammatory processes ) , sometimes the pelvic veins as a complication of obstetric and gynaecological procedures .
a 54-year - old male with history of human immunodeficiency virus ( hiv ) infection and intravenous drug abuse was hospitalized because of septic fever and lumbar pain .
clinically , edematous swelling of his external genitalia and left thigh , leg and ankle was appreciated , associated with mild pain and distal erythema . in the affected lower extremity ,
physical examination did not disclose significant dilatation of the superficial veins , absent peripheral pulses , or signs of arterial insufficiency .
laboratory tests disclosed anemia ( 8.7g / dl ) , low platelet count ( 84.00/mmc ) , and markedly raised c - reactive protein ( 305 u / l ) .
early color doppler study did not disclose acute abnormalities of both arterial and venous systems of the lower limbs .
initial clinical suspicion of infectious spondylo - diskitis was excluded by negative magnetic resonance imaging ( mri ) of the dorso - lumbar spine .
three days after admission , contrast - enhanced multidetector ct disclosed dilatation of the entire left femoral , external and common iliac veins with un - opacified lumen containing some gas , prominent enhancement of the venous wall and associated inflammatory stranding of the perivascular fat , findings consistent with septic thrombophlebitis [ figure 1 ] .
unenhanced multidetector computed tomography ( ct ) image ( a ) shows dilatation of left common iliac vein with intraluminal gas and inflammatory stranding of the perivascular retroperitoneal fat . contrast - enhanced ct scan ( b ) depicts dilated left iliac vein with unopacified lumen , gas bubbles and prominent enhancement of the vascular wall , findings consistent with septic thrombophlebitis . coronal reformations ( c , d ) document the entire extent of the left iliaco - femoral axis thrombosis , extending cranially to the caudal most portion of the inferior vena cava intensive medical treatment including antibiotics and anticoagulation with full - dosage low - molecular - weight heparin ( 6000 ui enoxaparin twice daily , prescribed for 3 months ) allowed clinical resolution of sepsis and normalization of laboratory inflammatory markers during three weeks . at discharge , the iliac and femoral veins appeared patent at color doppler ultrasound .
three months later , at ambulatory follow - up visit the patient was doing well and anticoagulation was discontinued .
at least partly related to drug impurities , complications of recreational drug abuse may involve different organs ( particularly the cardiovascular , respiratory , and musculoskeletal systems ) and are increasingly encountered in emergency departments .
deep venous thrombosis in intravenous substance users occurs secondary to superinfection from non - sterile injection technique in the femoral veins that are used when injection sites in the arms are exhausted.[24 ] infection with the hiv further increases the risk , because of the associated coagulation system abnormalities including increased levels of fibrinogen , d - dimer , plasminogen activator inhibitor-1 , and tissue - type plasminogen activator antigen .
therefore , septic thrombophlebitis should be taken in mind as a possible cause of persistent , often spiking fever despite broad - spectrum antibiotic therapy , associated with leg edema , flank and lower abdominal pain of variable intensity .
leukocytosis and abnormal inflammatory markers may vary depending on the host immune response , and hemocultures may disclose the causing organism , most usually s. aureus . as this case demonstrates , at ct
the hallmark signs of septic thrombophlebitis include vein enlargement with sharp vessel wall enhancement , partial or complete luminal non - opacification , often associated with abnormal density of the surrounding fat planes consistent with inflammatory stranding ; endoluminal gas bubbles may result from superinfection or may simply reflect injected . additionally , multiplanar reformations may help to visualize the entire extent of the venous thrombosis.[24 ] high clinical suspicion and prompt imaging assessment with contrast - enhanced multidetector ct are imperative to diagnose this uncommon yet serious complication , to prevent further complications such as systemic embolization particularly to the lungs , brain , and musculoskeletal system .
color doppler ultrasound is often limited by meteorism and large body structure , and should be therefore reserved for monitoring treatment response .
although optimal management remain controversial in literature , improved diagnosis by means of ct and adequate antibiotic and anticoagulant treatment has dramatically reduced the traditionally high mortality rates .
septic thrombophlebitis of the pelvic veins may occur secondary to non - sterile intravenous drug injection and represents an uncommon yet life - threatening condition , most usually manifesting with persistent spiking fever and limb edema . 
 risk is further increased in hiv - infected people . 
 high clinical suspicion and prompt imaging assessment with contrast - enhanced multidetector ct are necessary for correct diagnosis and staging , since early treatment prevents further complications such as systemic embolization .