AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Catscratch disease (CSD) was first described in mid 20th-century literature; the first individual with CSD was a 10-year-old boy in Paris, France. The signs and symptoms of CSD widely vary; regional adenopathy is the most common symptom. Many organ systems can be affected. A skin papule at the sight of inoculation often occurs prior to the development of adenopathy. CSD is the most common cause of chronic adenopathy in children. Typically, the incubation period is 3-10 days.

Kittens are more likely to transmit the infection than older cats. Owners of kittens younger than 12 months are 15 times more likely to develop CSD than owners of adult cats. Fleas are also most likely vectors for disease. More than 90% of patients infected with CSD have a recent history of contact with a cat, usually a kitten. Risk factors for CSD include ownership of a kitten younger than 12 months, a scratch or bite from a kitten, and ownership of at least one cat with fleas. CSD secondary to a dog bite has also been reported.¹

Pathophysiology

Most cases of CSD are caused by Bartonella henselae. The bacteria, formerly classified as Rochalimaea henselae, are slow-growing, fastidious, pleomorphic, gram-negative organisms. In addition to lymphatics, infection can affect the CNS, eyes, liver, spleen, bone, and lungs. Erythema nodosum and thrombocytopenia purpura have also been reported. The primary inoculation site and involved lymph nodes show a central area of avascular necrosis surrounded by lymphocytes. Histiocytes and giant cells are often present.

Frequency

United States

The incidence rate is believed to be at least 9.3 per 100,000 population or more than 22,000 cases of CSD per year. In temperate climates, CSD predominantly occurs in autumn and winter; in the tropics, seasonal changes in frequency of the disease are not observed. Hospitalization rates vary from 0.6-0.86 per 100,000 children. The median hospitalization charge for CSD has been estimated to be $46,140, and annual expenses are estimated to be about $3.5 million.

International

Distribution of CSD is worldwide. Incidence rates reflect cat populations in each country.

Mortality/Morbidity

CSD is usually self-limited and benign. Patients with prolonged courses of the disease usually fully recover. Reinfection is infrequent. Death caused by CSD in patients who are immunocompetent is extremely rare.

Sex

CSD is observed more frequently in males than females. This probably reflects an increased risk of exposure to infected kittens and an increased risk of bites and scratches from the infected animal.

Age

Although recent studies suggest that approximately 60% of cases of CSD occur in patients younger than 20 years, older literature suggests that incidence in this age group may have been as high as 80%.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• A history of contact with a cat, usually a kitten, in the previous 1-2 weeks is common in individuals with catscratch disease (CSD). The patient often remembers being bitten or scratched by the cat.
• The classic history of an individual with CSD is a local rash followed by adenopathy.
• • The rash is present in more than 90% of patients infected with the disease and usually lasts until adenopathy occurs, which is a period of 1-4 weeks.
  • The rash consists of one or more red papules that are 0.5 cm or less in diameter and appear at the site of inoculation, which is often a cat scratch or bite.
• Lymphadenitis usually persists 4-6 weeks but can last one year or longer.
• • Axillary nodes are most frequently affected, followed by cervical, submandibular, and preauricular nodes.
  • Single node involvement occurs in more than one half of individuals with CSD. The typical node size is 1-5 cm in diameter.
• Fever of unknown origin may be present in one third of patients with CSD.
• Fatigue is also present in one third of patients with CSD.
• Parinaud oculoglandular syndrome occurs in 2-3% of patients with CSD.
• CNS findings are present in 5% of patients with CSD and include headaches, mental status changes, seizures, myelitis, transient peripheral neuropathy, and retinitis.

Physical

• Skin lesions typically evolve from vesicular to erythematous papular lesions. Papules may have an overlapping crust. Soon after the onset of adenopathy, skin lesions may disappear.
• Affected lymph nodes are tender with red, warm, indurated skin over the nodes. Many of the lesions may suppurate. Occasionally, a sinus track may form. Nodes that drain may heal with scarring. Occasionally, node enlargement lasts 4-6 weeks.
• Fever may be present in one third of patients with CSD and may last 1-2 weeks. In a recent series of prolonged fever without a source, CSD was one of the most common diagnoses.²
• Fatigue is also present in one third of cases and may persist for weeks to months.
• Parinaud oculoglandular syndrome, which is characterized by unilateral conjunctivitis and regional lymphadenitis, occurs in 2-3% of patients with CSD.
• • In these patients, the site of inoculation is usually the eyelid or conjunctiva secondary to a lick, scratch, or bite. Subsequent rubbing of the eye often leads to spreading.
  • After a few weeks, the patient develops nonpurulent conjunctivitis, an ocular granuloma, or both. Preauricular adenopathy also develops.
  • Physical findings involving the eye resolve in a few months without residual damage.
• CNS findings occur in 5% of patients with CSD and include encephalitis, seizures, myelitis, peripheral neuropathy, and retinitis.
• • Headaches and mental status changes occur 2-3 weeks after onset of the disease and are frequently the initial findings of the encephalopathy.
  • Patients with encephalitis may have seizures.
  • Myelitis presents with extremity weakness, abnormal reflexes, sensory loss, and sphincter dysfunction.
  • Bell palsy has been described in patients with CSD.
  • Acute onset, self-resolving, recurrent expressive aphasia has been reported.
  • Other CNS findings include transient peripheral neuropathy and optic neuritis and neuroretinitis presenting as unilateral blindness.
  • Recovery from CNS manifestations may be slow; some individuals with CSD require one year or longer to recover from CNS manifestations.
• An individual with CSD may present with a fever of unknown origin. Adenopathy may not be present. Abdominal pain may be the initial finding, along with fever, for hepatosplenic CSD.
• Characterized by painful, tender, subcutaneous nodules on the skin, erythema nodosum may present 1-6 weeks after onset of adenopathy in less than 1% of patients with CSD. These nodules resolve without sequelae.
• A transitory rash may occur early in the course of the disease. Most commonly, the rash is an evanescent maculopapular rash.
• • Thrombocytopenia purpura is quite rare and is usually transient.
  • Osteomyelitis, manifesting by fever and bone pain, has been reported. 
  • A few patients with CSD have been described with osteolytic lesions but not true osteomyelitis. These patients do not have a fever or leukocytosis.
  • Sites of node involvement are remote from the site of inoculation of B henselae, suggesting hematogenous spread. Biopsy of these lesions demonstrates granulomatous reactions.
• Endocarditis with immune-mediated manifestations has been described. Immunocompromised patients may present with insidious back pain due to vertebral osteomyelitis. Other findings in immunocompromised patients include cysts in the liver and spleen, painful tumors, angiomatosis, and peliosis.

Causes

• CSD appears to be caused by B henselae.
• Afipia felis, at one time thought to be a major etiologic agent of CSD, has now been excluded as a significant cause.
• Disseminated illness occurs in less than 1% of patients with CSD. It is manifested by persistent spiking fever, hepatosplenomegaly, and abdominal pain associated with diffuse granulomatous liver and spleen.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Brachial cleft cyst
Dermoid cyst
Fungal infections
Histiocytosis X
Infectious mononucleosis
Lymphoma
Lymphogranuloma venereum
Thyroglossal cyst
Tumors

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• History and physical findings strongly suggest the diagnosis. Routine laboratory evaluation is usually not necessary or valuable.
• When necessary, confirmation can be established with histopathology tests.
• • Lymph node biopsy evaluation can be helpful. Biopsy findings depend on when in the course of the disease the biopsy is performed.
  • Early findings include lymphoid and reticular cell hyperplasia and arteriolar proliferation. Later, granulomas with central necrosis often appear along with multinucleated giant cells. Microabscesses appear later.
  • Polymerase chain reaction (PCR) can be useful in detecting the DNA of Bartonella species in clinical specimens; however, PCR remains primarily an experimental technique for catscratch disease (CSD) diagnosis.
  • Staining specimens with Warthin-Starry stains can show clumps of pleomorphic rods. These are usually found in the walls of blood vessels and in the microabscesses and macrophages that line the sinuses.
  • Liver and spleen biopsies may also show granulomas and abscesses.
  • Although difficult, Bartonella species can be grown from clinical species. The organism is fastidious and may take 9-40 days to grow on specialized medium.
• Confirmation can also be established with serology tests.
• • Most patients have measurable antibody titer to Bartonella species; however, distinguishing one Bartonella species from another is difficult using most serologic techniques.
  • Indirect immunofluorescence assay to B henselae performed by the Centers for Disease Control and Prevention (CDC) is 96% sensitive, and enzyme-linked immunoassay can be 71% sensitive.
• Skin testing is rarely used. In the past, material from infected lymph nodes was processed to make antigen used for skin testing. The test is no longer used because of the risk of transmitting pathogens.

Imaging Studies

• CT scan findings in patients with encephalopathy are usually not diagnostic.
• Ultrasound or CT scan findings may reveal multiple abnormalities (granulomatous inflammation) in the liver and spleen.

Other Tests

• EEG in patients with encephalopathy usually reveals diffuse slowing or focal abnormalities.

Procedures

• Cerebral spinal fluid (CSF) findings in patients with encephalopathy is usually not diagnostic.

Histologic Findings

Histologic findings in individuals with CSD progress over time. Lymphoid hyperplasia, reticular cell hyperplasia, and arteriolar proliferation are followed by granulomas with central necrosis. Microabscesses appear later.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

The need for and value of what constitutes appropriate therapy in persons with CSD has not been well studied. In most immunocompetent patients, catscratch disease (CSD) is self-limited, and symptoms resolve in 2-4 months. Antibiotic in vitro activity against B henselae does not correlate well with in vivo response.

Effective antibiotics used in treating CSD include rifampin, ciprofloxacin, trimethoprim-sulfamethoxazole (TMP-SMX), and gentamicin. Clarithromycin, azithromycin, and tetracycline are likely to be effective. Although data are lacking, patients with CSD who are treated should receive treatment for 10-14 days. Immunocompromised patients may require much longer courses of therapy. No specific dose recommendations are available for treating CSD.

• Normal doses of rifampin are 10-20 mg/kg/d orally every 12-24 hours, not to exceed 600 mg/d. Rifampin can cause hepatitis, particularly with underlying liver damage. Gastrointestinal, hematologic, and neurologic adverse effects are reported.
• Ciprofloxacin is not approved for administration in children. Ciprofloxacin, as with other quinolones, has been implicated in damaging cartilage in immature animals. These concerns have reduced the use of this class of drugs in pediatric patients. Adverse effects include gastrointestinal symptoms, dizziness, rash, seizures, headache, confusion, and tremors.
• TMP-SMX doses can include 8-12 mg/kg/d orally of TMP and 40-60 mg/kg/d orally of SMX every 12 hours. TMP-SMX can cause rashes and, occasionally, Stevens-Johnson syndrome. Anemia and neutropenia may occur, and a mild decrease in platelet count is common.
• The dose of intravenous gentamicin is 3-7.5 mg/kg/d orally every 8 hours. Serious toxic effects from these drugs are not common. Gentamicin may cause nephrotoxicity and ototoxicity.
• Do not administer sulfa drugs in patients with glucose-6-phospate dehydrogenase (G-6-PD) deficiency. Sulfa crystals may be deposited in the renal system if the patient is not adequately hydrated. Drug fever, serum sickness, and hepatitis are infrequent reactions.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Most immunocompetent patients completely recover without antibiotic therapy. Involvement of organ systems other than the lymph nodes, especially the neurologic system, or prolonged disease may be reason for antibiotic use.

Drug Category: Antibiotics

B henselae, a gram-negative bacillus, is sensitive to various antibiotics in vitro. Few clinical studies are available, but not all of the antibiotics to which the organism is sensitive in vitro are effective in vivo.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Deterrence/Prevention:

• Advise individuals to avoid bites, licks, and scratches from cats, especially kittens, to decrease risk of contracting catscratch disease (CSD).
• Advise individuals to control fleas on kittens to prevent spread of the disease among animals.

Complications:

• Neurologic sequelae include encephalitis, seizures, myelitis, retinitis, headache, mental status changes, and peripheral neuropathy. Other complications include erythema nodosum, hepatosplenic involvement, and thrombocytopenic purpura. Bone marrow involvement has been described in children with bone pain and fever.
• Bacillary angiomatosis and bacillary peliosis occur in patients who are immunocompromised and in those infected with human immunodeficiency virus (HIV).

Prognosis:

• Because the disease is usually self-limited, immunocompetent patients with Bartonella species infection, including severe CSD encephalopathy or encephalitis, generally completely recover. However, symptoms may persist for months.

Patient Education:

• To decrease risk of contracting CSD, advise patients and caregivers to avoid bites, licks, and scratches from cats, especially kittens.
• Advise patients with CSD and caregivers to control fleas on kittens to prevent spread of the disease among animals.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

Failure to diagnose CSD: In most cases, catscratch disease (CSD) has little impact on outcome and prognosis. Most cases of CSD are self-limited and antimicrobial therapy is usually not required. However, diagnosis of CSD allows termination of the workup for other causes of symptoms. It also enables the physician to give the patient and family an idea about time course of the disease and prognosis, which is usually quite good.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

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2. Malatack JJ, Jaffe R. Granulomatous hepatitis in three children due to cat-scratch disease without peripheral adenopathy. An unrecognized cause of fever of unknown origin. Am J Dis Child. Sep 1993;147(9):949-53. [Medline].
3. Anderson B, Sims K, Regnery R, et al. Detection of Rochalimaea henselae DNA in specimens from cat scratch disease patients by PCR. J Clin Microbiol. Apr 1994;32(4):942-8. [Medline].
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9. Fox JW, Studley JK, Cohen DM. Recurrent expressive aphasia as a presentation of cat-scratch encephalopathy. Pediatrics. Mar 2007;119(3):e760-3. [Medline].
10. Hajjaji N, Hocqueloux L, Kerdraon R, Bret L. Bone infection in cat-scratch disease: a review of the literature. J Infect. May 2007;54(5):417-21. [Medline].
11. Hipp SJ, O'Shields A, Fordham LA, et al. Multifocal bone marrow involvement in cat-scratch disease. Pediatr Infect Dis J. May 2005;24(5):472-4. [Medline].
12. Margileth AM. Dermatologic manifestations and update of cat scratch disease. Pediatr Dermatol. Feb 1988;5(1):1-9. [Medline].
13. Margileth AM, Wear DJ, English CK. Systemic cat scratch disease: report of 23 patients with prolonged or recurrent severe bacterial infection. J Infect Dis. Mar 1987;155(3):390-402. [Medline].
14. Peter, G, ed. Cat scratch disease. In: Red Book: Report of the Committee on Infectious Disease. 24^th ed. 1997:165-6.
15. Reynolds MG, Holman RC, Curns AT, et al. Epidemiology of cat-scratch disease hospitalizations among children in the United States. Pediatr Infect Dis J. Aug 2005;24(8):700-4. [Medline].
16. Rolain JM, Chanet V, Laurichesse H, et al. Cat scratch disease with lymphadenitis, vertebral osteomyelitis, and spleen abscesses. Ann N Y Acad Sci. Jun 2003;990:397-403. [Medline].
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18. Tolan RW Jr, Schibler KR, Galliani CA, Kleiman MB. Unusual systemic, pseudomalignant manifestations of cat-scratch disease in siblings. Pediatr Infect Dis J. Dec 1990;9(12):913-6. [Medline].
19. Wong MT, Dolan MJ, Lattuada CP Jr, et al. Neuroretinitis, aseptic meningitis, and lymphadenitis associated with Bartonella (Rochalimaea) henselae infection in immunocompetent patients and patients infected with human immunodeficiency virus type 1. Clin Infect Dis. Aug 1995;21(2):352-60. [Medline].

Article Last Updated: Sep 20, 2007