- MULTIFOCAL TO COALESCING EXUDATIVE EPIDERMITIS
- STAPHYLOCOCCUS HYICUS
- University of Pennsylvania
- Greasy pig disease, or exudative epidermitis, is caused by Staphylococcus hyicus, a gram positive bacterium. The disease occurs most commonly following introduction of carrier animals into a naive herd. The pathogenesis of exudative epidermitis is not completely known; however, trauma from fighting, unclipped teeth, rough bedding, or other factors leading to exposure of the dermis may allow the bacteria to establish the infection.(6,12) Initially, there is reddening of the skin with multiplication of bacteria on skin surface and growth between keratinocytes. In infected skin, there is generally marked inflammation with hyperplasia of the stratum corneum and neutrophilic infiltration followed by epidermal erosion. The most important factor in pathogenesis of infection is the production of exfoliative toxins. Exudative epidermitis is regarded as a porcine homologue of Staphylococcal Scalded Skin Syndrome (SSSS) or bullous impetigo in humans. SSSS results in loss of keratinocyte cell-to-cell adhesion and leads to blister formation.