Durometer measurements of skin induration in venous disease

The degree of skin induration (lipodermatosclerosis) around venous ulcers has prognostic significance; however, objective measurements are needed to assess the induration. The durometer, an engineering instrument used to measure the hardness of metals and plastic, has recently been adapted to assess skin induration.

The purpose of this study was to measure skin induration and its relationship to skin ulceration by the use of a durometer, and to determine the influence of edema, if any, on durometer measurements.

The degree of skin induration on the medial leg was determined in six sequential, nonselected patients with lipodermatosclerosis and leg ulcers, and in five normal volunteers by using a blinded observer's clinical score (0 = normal to 3 = maximal induration) and a hand-held Type 0 durometer. In addition, durometer readings in 14 patients with edema and eight control subjects were taken on the tibia, the dorsum of the foot, and behind the ankle.

Durometer readings in patients with leg ulcers and lipodermatosclerosis diminished as one measured from the superior edge of the ulcer to the knee (r = 0.925). The higher the clinical skin score the higher were the durometer readings (P = 0.0062). The presence of edema did not influence durometer measurements.

The durometer is an effective and reliable instrument for measuring the degree of skin induration in venous ulceration and its readings are not affected by edema. Ulcers occur in skin most affected by lipodermatosclerosis.