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Erysipelothricosis is infection caused by Erysipelothrix rhusiopathiae. The most common symptom is erysipeloid, an acute but slowly evolving localized cellulitis. Diagnosis is by culture of a biopsy specimen or occasionally PCR testing. Treatment is with antibiotics.
Erysipelothrix rhusiopathiae (formerly E. insidiosa) are thin, gram-positive capsulated, nonsporulating, nonmotile, microaerophilic bacilli with worldwide distribution; they are primarily saprophytes. They may infect a variety of animals, including insects, shellfish, fish, birds, and mammals (especially swine). In humans, infection is chiefly occupational and typically follows a penetrating wound in people who handle edible or nonedible animal matter (eg, infected carcasses, rendered products [grease, fertilizer], bones, shells). Most commonly, patients handle fish or work in slaughterhouses. Infection can also result from cat or dog bites. Nondermal infection is rare, usually occurring as arthritis or endocarditis.
Symptoms and Signs
Within 1 wk of injury, a characteristic raised, purplish red, nonvesiculated, indurated, maculopapular rash appears, accompanied by itching and burning. Local swelling, although sharply demarcated, may inhibit use of the hand, the usual site of infection. The lesion's border may slowly extend outward, causing discomfort and disability that may persist for 3 wk. The disease is usually self-limited. Regional lymphadenopathy occurs in about one third of cases. It rarely becomes generalized cutaneous disease, which is characterized by purple skin lesions that expand as the lesion's center clears, plus bullous lesions at the primary or distant sites.
Bacteremia is rare and is more often a primary infection than dissemination from cutaneous lesions. It may result in septic arthritis or infective endocarditis, even in people without known valvular heart disease. Endocarditis tends to involve the aortic valve, and the mortality rate and percentage of patients needing cardiac valve replacement are unusually high. Rarely, CNS, intra-abdominal, and bone infections occur.
Diagnosis
Culture of a full-thickness biopsy specimen is superior to needle aspiration of the advancing edge of a lesion because organisms are located only in deeper parts of the skin. Culture of exudate obtained by abrading a florid papule may be diagnostic. Isolation from synovial fluid or blood is necessary for diagnosis of erysipelothrical arthritis or endocarditis. E. rhusiopathiae may be misidentified as lactobacilli. PCR amplification may aid rapid diagnosis.
Treatment
For localized cutaneous disease, usual treatment is penicillin V or ampicillin (500 mg po q 6 h), ciprofloxacin (250 mg po q 12 h), or clindamycin (300 mg po q 8 h) for 7 days. Cephalosporins are also effective. Daptomycin and linezolid are active in vitro. Tetracyclines and macrolides may no longer be dependable. E. rhusiopathiae are resistant to sulfonamides, aminoglycosides, and vancomycin.
Severe diffuse cutaneous or systemic infection is best treated with IV penicillin G (2 to 3 million units q 4 h), ceftriaxone (2 g IV once/day), or a fluoroquinolone (eg, ciprofloxacin 400 mg IV q 12 h, levofloxacin 500 mg IV once/day).
Endocarditis is treated with penicillin G 25,000 to 30,000 units/kg IV q 4 h for 4 wk. Cephalosporins and fluoroquinolones are alternatives.
The same drugs and doses are appropriate for arthritis (given for at least 1 wk after defervescence or cessation of effusion), but repeated needle aspiration drainage of the infected joint is also necessary.
Last full review/revision April 2013 by Larry M. Bush, MD; Maria T. Perez, MD
Content last modified April 2013
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