The mechanism for periorbital and facial edema is similar to that for edema of the extremities. Thus, increased backpressure of the veins will cause periorbital edema in right heart failure, constrictive pericarditis, advanced pulmonary emphysema, and thrombosis or extrinsic obstruction of the superior vena cava (as in mediastinal tumors). High blood pressure from acute glomerulonephritis and malignant hypertension will cause periorbital and facial edema. Low serum albumin will lead to periorbital and facial edema in nephrosis and cirrhosis. Mucoprotein in the subcutaneous tissue will cause periorbital edema in hypothyroidism.
Other causes for periorbital edema are not associated as frequently with edema in the extremities. Allergic or inflammatory dilatation of the capillaries around the eyelids will cause periorbital edema in dermatomyositis and trichinosis. A thrombosed cavernous sinus will also cause periorbital edema, but this is similar to thrombophlebitis of an extremity. Local causes for periorbital edema include orbital cellulitis, urticaria, angioneurotic edema, contusions, and other orbital trauma. The workup for periorbital edema is similar to that for edema of the extremities (see page 147).