STUDIES ON BLISTERS PRODUCED BY FRICTION .I. RESULTS OF LINEAR RUBBING AND TWISTING TECHNICS

[摘要] Over 300 friction blisters were produced experimentally on 117 volunteers. The technics employed for both linear rubbing and twist rubbing are described. An improved linear rubbing apparatus was constructed. This permits the measurement of the factors involved in the production of frictional injury to the skin. The influence of moisture on skin friction is confirmed. Intermediate degrees of moisture at the rubbing interface tend to increase skin friction, whereas extremes of dryness and wetness tend to decrease friction. Friction blisters do not usually occur clinically on thin skin because it lacks the thick and resistant stratum corneum for the blister roof. Nor do they usually occur on loose skin, because it lacks the tight adherence of the skin to underlying structures necessary for shearing effects to be produced in the epidermis. Histologic sections of a friction blister on thin and thick skin show an intra-epidermal bulla with necrosis and degeneration of the spinous cells. The blister roof consists of the stratum corneum, stratum granulosum, and some amorphous cellular debris. Friction blister formation occurs in 2 stages: 1st, the production of an intra-epidermal cleft or space due to surface forces transmitted through a sufficiently resistant stratum corneum and granulosum to produce a shearing effect; and 2nd, the influx of fluid into this cleft. During the period in which arterial circulation is arrested or the hemodynamic pressure to the part substantially reduced, little or no free fluid accumulates within the blister compartment.