Lymphedema of the upper limb in patients with psoriatic arthritis.

Upper limb lymphedema occurs rarely in rheumatoid arthritis (RA) but has been reported only once in psoriatic arthritis (PsA). The pathogenesis is unknown. This study describes four patients (three women) with upper limb lymphedema, chronic symmetrical polyarthritis, and psoriasis. Three were seronegative, diagnosed PsA; one was seropositive. Age ranged from 39 to 64 years, duration of psoriasis was 6 to 42 years, and duration of arthritis was 6 to 12 years. Onset of lymphedema was unrelated to the extent or severity of arthritis, and no other cause for this condition was identified. Radiological appearances ranged from mildly abnormal to advanced joint destruction, but carpal disease was prominent in all patients. Lymphoscintigraphy was abnormal in three subjects. Lymphedema became bilateral in two and was associated with radiological progression of arthritis. Disease-modifying therapy produced improvement of lymphedema in two patients and correction of the lymphoscintigraphic abnormality in one. This study describes upper limb lymphedema in patients with PsA and suggests that local synovitis may play a role in its pathogenesis.