Erysipeloid
Synonyms and Keywords: Erysipelotrichosis, Rose fish-handlers disease, Rosenbach's disease, Rosenbach's Erysipeloid or Erysipeloid of Rosenbach

# Overview
Erysipeloid is an occupational infection resulting from introduction of Erysipelothrix rhusiopathiae (formerly E. insidiosa) into a traumatized patch of skin. Clinically, the disease is observed as erythematous edema, with well-defined and raised borders. Lesions are mostly localized to the back of the hand. Vesicular, bullous, and erosive lesions may also be present. The lesions are usually asymptomatic and occasionally associated with pain, fever, and  mild pruritus. In addition to cutaneous infection, E. rhusiopathiae may be complicated by acute or subacute endocarditis. Endocarditis is rare and has a male predilection. It usually occurs in previously damaged valves, predominantly the aortic valve. Endocarditis does not occur in patients with valvular prostheses and is not associated with intravenous drug misuse. Eysipeloid is a clinical diagnosis. Affected patients usually present with a history of occupational exposure to unprocessed fish or meat with characteristic cutaneous lesions. It typically  gains entry through abrasions in the hand. Bacteremia and endocarditis are uncommon but serious complications. Erysipeloid is frequently misidentified due to the rarity of reported cases.

# Historical Perspective
- In 1884, Friedrich Julius Rosenbach (also called Anton Julius Friedrich Rosenbach), a German physician and microbiologist, was the first to accurately describe the association between Erysipelothrix rhusiopathiae and the development of erysipeloid.
- Erysipelothrix rhusiopathiae was first isolated from mice in 1880 by Robert Koch. 

# Classification
Erysipeloid may be classified into the following categories according to the severity of the condition:

## Localized cutaneous erysipeloid
- Usually a mild, localized infection
- Patients present with localized swelling and redness of the skin
- Commonly referred to as "erysipeloid of Rosenbach"

## Diffuse cutaneous erysipeloid
- Patients may present with fever

## Generalized or systemic erysipeloid
- Manifests as bacteremia with associated complications (e.g., endocarditis, arthritis)

# Pathophysiology

## Pathogenesis
Erysipeloid results from an infection with Erysipelothrix rhusiopathiae after an area of skin containing an abrasion comes into contact with contaminated fish, poultry, or raw meat.
The organism is known for its high environmental resistance. Various virulence factors have been implicated in the pathogenicity of erysipeloid. Following infection in the skin, the organism produces certain enzymes that help it dissect its way through the tissues. Significant among them are hyaluronidase and neuraminidase. Neuraminidase has been shown to play vital role in the attachment of Erysipelothrix rhusiopathiae. This subsequently aids in the invasion of host cells. The role of hyaluronidase in the disease process is not well understood. The presence of a heat labile capsule has been reported as being important in virulence.. At the same time, the patient's immune response is activated to fight against the organism. Failure of the immune surveillance leads to systemic dissemination of the bacteria to the heart, brain, kidney, vascular system, joints, central nervous system, and lungs. The heart is the most commonly affected systemic organ.

## Associated conditions
The following conditions are associated with erysipeloid:
- Endocarditis
- Hodgkins lymphoma
- Use of gemcitabine
- Sweet's syndrome
- Renal failure
- Septic arthritis
- Polyarthralgia

# Causes
Erysipeloid is caused by an infection with Erysipelothrix rhusiopathiae, a Gram-positive rod bacteria. Infection with Erysipelothrix rhusiopathiae commonly results from contact between skin containing abrasions or lesions and contaminated fish, poultry, or raw meat. 

# Differentiating Erysipeloid from Other Diseases
Erysipeloid must be differentiated from the following conditions:
- Abscess
- Cellulitis
- Contact dermatitis
- Erysipelas
- Furuncle
- Insect or animal bites
- Ulcer

# Epidemiology and Demographics
Infection with E. rhusiopathiae occurs worldwide in a variety of animals, including sheep, rabbits, turkeys, birds, cattle, rats, and fish.

## Race
No racial predilection is recognized for erysipeloid.

## Sex
Males are more commonly affected with erysipeloid than females because of the relative frequency of occupational exposure.

## Age
Erysipeloid can affect any age group.

# Risk Factors
Erysipeloid is most common among individuals who have direct contact with infected animals. 
People in the following occupations are at the highest risk for contracting the condition:
- Fishermen
- Farmers
- Slaughterhouse workers
- Butchers
- Meat handlers
- Agricultural workers
Erysipeloid is observed most frequently during the summer and early fall.

# Screening
There is no established screening modality for erysipeloid.

# Natural History, Complications, and Prognosis
Cutaneous forms of the disease usually resolve spontaneously. The prognosis is excellent with appropriate antibiotics. Inadequate treatment can lead to complications such as endocarditis or arthritis.
Antibiotic-resistant strains will complicate therapy. Repeated infection may result in the development of allergies. Reduced immunity may complicate the infection. Individuals with the severe, systemic form of erysipeloid may suffer irreversible neurological damage. Endocarditis may result in long-term valvular heart disease. Septic arthritis may result in long-term joint disease.

# Diagnosis

## History and Symptoms
Patients with erysipeloid usually present with a history of occupational exposure to unprocessed fish or meat.
Symptoms may include:
- skin irritation
- localized burning sensation
- itching
- pain
Patients with systemic infections may present with:
- fever
- chills
- fatigue
- malaise

## Physical Examination
Physical examination of patients with erysipeloid is usually remarkable for lesions with the following features:
- purplish-red rash with associated burning and itching
- crusted formation
- erythematous edema or infiltrative plaque with raised borders
- localized tenderness
- joint lesions may manifest as tenosynovitis
- individuals with endocarditis may have a heart murmur noted on examination

## Laboratory Findings
Laboratory investigations are usually not needed to diagnose erysipeloid since the diagnosis is mostly clinical.

## Imaging Findings
CT scans may be helpful in the diagnosis of erysipeloid endocarditis. A CT scan may show vegetations, paravalvular abscesses, and/or pseudoaneurysms.

# Treatment

## Medical Therapy
The treatment of choice is intramuscular benzathine benzylpenicillin, oral penicillin, or intramuscular procaine benzylpenicillin. 
Patients who are allergic to penicillin may be treated with erythromycin or doxycycline.

## Antimicrobial Regimen
- Preferred regimen (1): Penicillin 500 mg qid for 710 days
- Preferred regimen (2): Amoxicillin 500 mg tid for 710 days
- Erysipelothrix rhusiopathiae 
- 1. Erysipeloid of Rosenbach (localized cutaneous infection)
- Preferred regimen (1): Penicillin G benzathine 1.2 MU IV single dose
- Preferred regimen (2): Penicillin VK 250 mg PO qid for 5-7 days
- Preferred regimen (3): Procaine penicillin 0.6-1.2 MU IM qd for 5-7 days
- Alternative regimen (1): Erythromycin 250 mg PO qid for 5-7 days
- Alternative regimen (2): Doxycycline 100 mg PO bid for 5-7 days
- 2. Diffuse cutaneous infection
- Preferred regimen: See localized infection
- 3. Bacteremia or endocarditis
- Preferred regimen: Penicillin G benzathine 2-4 MU IV q4h for 4-6 weeks
- Alternative regimen (1): Ceftriaxone 2 g IV q24h for 4-6 weeks
- Alternative regimen (2): Imipenem 500 mg IV q6h for 4-6 weeks
- Alternative regimen (3): Ciprofloxacin 400 mg IV q12h for 4-6 weeks
- Alternative regimen (4): Daptomycin 6 mg/kg IV q24h for 4-6 weeks
- Note: Recommended duration of therapy for endocarditis is 4 to 6 weeks, although shorter courses consisting of 2 weeks of intravenous therapy followed by 2 to 4 weeks of oral therapy have been successful.

## Surgery
Surgery is usually not necessary for the management of erysipeloid. However, in rare cases with massive valvular destruction complicating endocarditis, surgical valvular replacement may be needed.

# Prevention

## Primary prevention
Effective measures for the primary prevention of erysipeloid include:
- Individuals whose work involves handling raw meat, fishing, and/or agricultural jobs should wear protective gloves when possible to avoid infection with contaminated food.
- Restriction of food-handling in people diagnosed with erysipeloid.

## Secondary Prevention
There are no established methods of secondary prevention for erysipeloid.