A 38-year-old woman presented with a persistently swollen left leg. The patient related that the swelling postdated a vague left calf injury incurred 6 months previously. Multiple physician evaluations (including repetitive emergency room visits) were inconclusive. Serial venous duplex ultrasonography, plain film tibial or fibular radiography, contrast venography, abdominopelvic computed tomography (CT), and a triple-phase bone scan were normal. Magnetic resonance imaging (MRI) was remarkable only for soft tissue swelling.
Examination revealed significant lymphedematous swelling of the left lower extremity. A peculiar fusiform swelling existed that abruptly terminated near the knee. Multiple horizontal indentations, depressions, and abrasions were identified along the popliteal fossa, proximal calf, and distal thigh (Figure 73-1). Factitial edema from a constricting band or tourniquet to the extremity was suspected.1
factitial edema of the left lower extremity. Multiple horizontal indentations, depressions, and abrasions exist along the popliteal fossa, proximal calf, and distal thigh. Note abrupt termination of the swelling at the level of the popliteal fossa. The contralateral extremity is normal.
Factitial or factitious edema is a rare cause of upper or lower extremity swelling caused by the repetitive application of a constrictive band or tourniquet. It has also been called voluntary edema or artificial edema, and over time it can mimic true lymphedema. According to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, factitious disorders are characterized by the intentional production or feigning of physical or psychologic signs or symptoms and a need to assume a sick role.2 Most patients with factitial edema present to multiple providers over a period of months to years and often undergo multiple diagnostic studies before eventual diagnosis.
It is usually unilateral, and patients often apply the tourniquet to the nondominant limb. Although typically affecting the lower extremity, factitious edema has been reported in the upper extremity. In one case report both the upper and lower extremities were involved.3 There are only a few case reports in the literature, thus the true incidence of factitial edema is unknown.
ETIOLOGY AND PATHOPHYSIOLOGY
With placement of a tourniquet, venous return is directly impaired, leading to increased hydrostatic pressure and fluid extravasation into adjacent soft tissue. Lymphatic return itself initially is normal or even increased,4 though over time the lymph vessels can become fibrosed, especially directly under the site of the tourniquet placement.5 It is conceivable that unabated increased hydrostatic pressure ultimately overwhelms lymphatic clearance and eventuates in clinical lymphedema. Reported associated psychologic issues include anxiety, depression, and conversion disorder. In contradistinction to malingering, which involves a conscious decision to self-harm, the factitial edema patient is unconsciously motivated.