Characterization of sulfur mustard vapor-induced cutaneous lesions on haired guinea pigs

Sulfur mustard (2,2'-dichlorodiethyl sulfide, HD) is a potent vesicating (blistering) agent. In this report, we describe the time-course and the dose-dependent response following cutaneous exposure to sulfur mustard (HD) in the haired guinea pig model. The purpose of this study was to evaluate the usefulness of the haired guinea pig as a vesicant research model.

Seventy-two animals were divided into nine groups of eight animals each. Hair on the dorsal side of each animal was removed by clipping with an electric clipper followed by application of a chemical depilating agent (MAGIC Shaving Powder). Six dorsal skin sites on each animal of a given group were exposed to saturated HD vapor (1.4 mg/l) for one of nine exposure times between 0-8 min. Lesions were evaluated for erythema (reflectance colorimeter) and edema (ultrasound imaging) at 4, 6, 12, and 24 h postexposure. Damage at the dermal-epidermal junction (DEJ) was evaluated by histopathology at 24 h postexposure.

We observed that the hair removal process was time-consuming, produced significant initial erythema, and resulted in increased dorsal skin sensitivity to low HD exposure levels. The time-course of exposure response to HD was observed to be dose-dependent and similar to the hairless guinea pig model.

The haired guinea pig is inferior to the hairless guinea pig as a vesicant model due to the complications resulting from the hair removal process. However, the haired guinea pig is a useful model for evaluating the cutaneous effects of HD vapor and can be developed into a routine screening tool for the evaluation of topical barriers against HD vapor exposure.