E. rhusio pathiae can infect mammals, birds, fish, shellfish, and insects. Human infection results from handling dead infected animal parts. Most cases of skin infection occur during the summer and early fall. Infection is almost always the result of occupational exposure of slaughterhouse workers, butchers, fishers, farmers, and veterinarians. The organism is usually traumatically inoculated.
Skin infection is associated with intense inflammation in the dermis.
Bacilli remain extracellular and are often located deep in the skin near capillaries, where the organism can gain entry into the bloodstream. Two to seven days after skin inoculation, a purplish-red, nonvesicular area arises with a sharply defined, raised, serpiginous border. Lesions most often develop on the face and hands. Proximal regions of the hand and fingers are involved, whereas the distal phalanges are usually spared. Over time, the central part of the lesion begins to heal, resulting in a pale center surrounded by a fiery-red outer border.