Fish Handler’s Disease
When cleaning marine fish or shellfish, the handler frequently creates small nicks and scrapes in his skin, usually on his hands. If these become infected with the bacteria Erysipelothrix rhusopathiae, a skin rash may develop within two to seven days. The rash appears as a red to violet-colored area of raised skin surrounding the small cut or scrape, with warmth, slight tenderness, and a well-defined border. The sufferer should be treated with penicillin, cephalexin, or ciprofloxacin for one week.
http://www.wfubmc.edu/besthealth/ODH/fish_handler.htm