Oedema protein concentrations for differentiation of cellulitis and deep vein thrombosis.

The differentiation between cellulitis and deep vein thrombosis was investigated in a series of patients with acutely swollen, painful, red legs. Oedema-fluid protein concentrations (as mean [SD]) were significantly higher in patients with cellulitis than in those with deep vein thrombosis (19.8 g/l [5.0] vs 5.85 g/l [1.6]), and the oncotic pressure of oedema-fluid was also significantly higher in cellulitis (6.3 mm Hg [1.3] vs 2.1 mm Hg [0.6]). In hospitals where phlebography, plethysmography, or doppler ultrasound are not available, measurement of oedema-fluid protein concentrations may be a rapid and inexpensive guide to the cause of a red, swollen leg.