Phlegmasia alba dolens describes the initial stage in the presentation of deep iliac vein thrombosis with partial impairment of arterial flow resulting in edema and "milky" appearance of the involved limb. Predisposing conditions consist of malignancy, hypercoagulability, ulcerative colitis, heart failure, mitral valve stenosis, pregnancy, oral contraceptive use, surgery, immobilization and antiphospholipid syndrome.
Phlegmasia alba dolens is usually seen in the lower extremities, especially in the left leg and consists of edema, pain and white color of the skin (caused by venous stasis, as a consequence of femoral vein thrombosis, thus the term "alba"), because cyanosis has not occurred yet, as phlegmasia alba precedes phlegmasia cerulea and arterial compromise is not as severe. The white color of the skin is caused by edema, not vasospasm, as initially postulated. Symptoms occur abruptly or gradually and progress to weakness, paresthesia, skin lesions like bullae and compartment syndrome, as collateral vessels become affected. The end stage is represented by venous gangrene and shock  . Arterial pulses in the affected limb are weak or absent at this stage.
When facing phlegmasia alba dolens patients, the physician should search for and eliminate all the triggering factors highlighted above, keeping in mind that in one tenth of cases a predisposing factor cannot be found. Since malignancy is found in 20-40% of patients, this kind of pathology should be carefully looked for .
Clinical examination should differentiate this condition from symmetric peripheral gangrene, characterized by a patent arterial bed, occlusion of venules and capillaries  and disseminated intravascular coagulation. However, this disease also involves tegument area not belonging to limbs, making clinical differential diagnosis easier.
If the diagnosis is not established in this stage, the clinical status deteriorates due to progression to complications like pulmonary embolism and venous gangrene, potentially life- threatening conditions  .
The diagnosis of Phlegmasia alba and cerulea dolens is a clinical one, but imaging methods can help establish the presence of venous thrombosis.
The most widespread diagnosis method is ultrasonography, with duplex ultrasonography being more accurate, if available. Deep vein thrombosis is suggested by a dilated, non-compressible vein with no spontaneous blood flow and hyperechoic masses inside, represented by thrombi . Being a portable and noninvasive method, it tends to replace contrast venography, that still represents the gold standard for diagnosis in uncertain cases. Technical difficulties may be encountered when trying to perform a venography, as extensive thrombosis prevents proper visualization of the venous system; in this case, the venous system belonging to the affected leg can be approached via the contralateral femoral vein or via the upper extremity veins in order to obtain at least some information about the iliocaval system. In patients where the extent of the thrombosis cannot be properly evaluated, computer tomographic venography and magnetic resonance venography can be performed . These methods have a supplementary advantage, represented by the fact that they can describe associated venous abnormalities or pelvic pathological processes compressing the iliac veins.