Erysipeloid is an infection with the gram-positive bacillus Erysipelothrix rhusiopathiae, which is also an agent of disease in animals, especially swine. The bacterium is transmitted when traumatized human skin comes into contact with an infected animal or animal meat; therefore, farmers, cooks, butchers, and fisherman are most at risk.

Erysipeloid is predominantly a self-limiting disease affecting the skin in either a localized or diffuse form, but occasionally may cause a serious systemic illness in which the most common manifestation is endocarditis. Skin lesions consist of violaceous plaques and are most often confined to the hands. There is often associated pain and pruritus.

The lesions of localized cutaneous erysipeloid often resolve without treatment in 3-4 weeks but may recur. Therefore, treatment with antibiotics is indicated in all forms of erysipeloid.

Erysipeloid can be differentiated from cellulitis on the basis of location (fingers and hands), animal exposure, and more violaceous appearance.