Erysipeloid is an infection of the skin caused by the gram-positive bacillus Erysipelothrix rhusiopathiae. The bacterium is transmitted when traumatized human skin comes into contact with an infected animal or animal meat; therefore, farmers, cooks, butchers, and fishermen are most at risk. Erysipeloid is transmitted by several animals, particularly pigs, but also sheep, rabbits, chickens, turkeys, ducks, emus, scorpion fish, and lobsters. The disease is rare in children.

Erysipeloid is characterized by erythematous to violaceous well-defined plaques with edema and raised borders. Vesicles, bullae, and erosions can also be present. The lesions of erysipeloid are generally located on the back of the hands and/or fingers. They are most often asymptomatic, but some patients may report mild pain, pruritus, or fever.

The diffuse / generalized form is rare and is characterized by similar cutaneous lesions in a widespread distribution. Unlike localized erysipeloid, patients with the diffuse / generalized form often report fever, lymphadenitis, and arthralgias.

In addition to the localized and diffuse cutaneous disease detailed above, the bacterium can also cause systemic disease, most often in the form of acute or subacute endocarditis. Endocarditis is rare and usually affects previously damaged valves.

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.