Lower extremity swelling in a patient with psoriatic arthritis

Swelling of an extremity secondary to psoriatic arthritis is a rare condition that typically occurs unilaterally, in the upper extremities, but can progress to involve multiple extremities. We report a patient with psoriatic arthritis who developed lower extremity swelling consistent with lymphedema that was unresponsive to traditional therapy. The pathophysiology of this disease may involve either tenosynovial involvement or lymphatic dysfunction. Clinical exam may help differentiate between the two types, and magnetic resonance imaging and/or lymphoscintigraphy can be used for more definitive diagnosis. In addition, other causes of extremity edema need to be evaluated. Recommendations for diagnosis and treatment of patients with this disease are discussed.