Sonographic appearance of pseudopodagra in Behçet's disease.

Arthritis of the fi rst metatarsophalangeal (MTP) joint of a different cause than gout is identifi ed by the term pseudopodagra. Although the majority causes of pseudopodagra are deposits of other micro crystals, there has been other rare cause, such as Behcet’s disease.1,2 We present the case of a patient with a pseudopodagra due to Behcet’s disease. A 43-year-old female patient suffering from Behcet’s disease for 10 years presented to the emergency department (ED) with discomfort in her right MTP joint. The onset was characterized by acute pain, swelling, erythema, tenderness, and limitation of movement of the fi rst MTP joint of the right foot. The patient denied any fever, chills, trauma, urethral symptoms, conjunctivitis, or history of gout. She had a past several attacks affecting oligoarticular involving knees and ankles. There was no family history of rheumatic disease. On physical examination, she was afebrile and all vital signs were normal. The area overlying her fi rst MTP joint was red, hot, swollen, and exquisitely tender to touch and to any movement of the great toe. The skin was not disrupted, and no lymphangitis or adenopathy was present. All other joints were normal, as was the remainder of the physical examination. Patient refused arthrocentesis procedure. We preferred ultrasound imaging as a fi rst line imaging technique instead of magnetic resonance imaging in order to save time. Grayscale ultrasound examination of dorsal aspect of 1st MTP showed marked synovial thickening (arrows) and minimal synovial fl uid (arrowhead) (Fig. 1A). There was no gouty tophus at the MTP joint. On power doppler imaging increased color signals are seen within the hyperthrophic synovium consistent with hyperemia (Fig. 1B). On left side, minimal concentric proliferation of synovial lining cell tissue and synovial fl uid (arrowhead) was seen (Fig. 2A). There were no color signals within the synovium on the 1st MTP of the left foot (Fig. 2B). Preliminary diagnosis was pseudopodagra rather than metatarsophalangeal arthritis because signifi cant extra-articular soft tissue changes were evident. Soft tissue changes can occur Fig. 1 – A, Grayscale ultrasound examination of dorsal aspect. B, Power doppler imaging increased color signals.