Suction Blister Wounding,Morphological and Functional Aspects

Abstract

The blister wound (eclited by vacuum, 200 mmHg below atmospheric for 2.5 hours, diameter of exposed skin site 4 mm, epidermal blister roof excised) can be used both as a standardized human wound model for study of micro- circulatory events and as a clinical means of achieving efficient transdermal drug delivery. In this study, vital microscopy assessment of the superficial micro- vessels of the wound bed in volunteers revealed that only a small proportion of the papillary loops was damaged when epidermis was split off. Histological ly, in the pig, a mild inflammatory reaction was noted, reaching only the mid- dermis, and subsiding within a few days. By means of laser Doppler flowmetry, two separate peaks of dermal hyperemia were observed during the suctioning. Once the negative pressure had been released, a hyperemic reaction was observed that lasted for several days. The wound flowmetry values were distinctly above those observed after an arterial occlusion on adjacent, intact skin. Slight itching and pricking sensations in the wound may be associated with activation of a pain- related local axon reflex, which in turn may be a major cause of the hyperemia.