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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 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.
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 or enterococci. PCR amplification may aid rapid diagnosis.
Treatment
For localized cutaneous
disease, usual treatment is penicillin V, ampicillin , ciprofloxacin , or erythromycin (macrolides may not be consistently active) 500 mg po qid for 7 days. Tetracyclines and cephalosporins are also effective. E. rhusiopathiae are resistant to sulfonamides and vancomycin .
Severe diffuse
cutaneous or systemic infection is best treated with IV penicillin G (12 to 20 million units/day), ceftriaxone (2 g IV once/day), or a fluoroquinolone (eg, ciprofloxacin 400 mg IV q 12 h).
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 December 2009 by Larry M. Bush, MD; Maria T. Perez, MD
Content last modified December 2009
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