Approach Considerations
Controlled studies on treatment of cat scratch disease (CSD) are lacking. Thus, treatment recommendations are based on case reports, reviews, a single controlled trial, and anecdotal data. Practice guidelines for the diagnosis and management of skin and soft-tissue infections, including CSD, have been established. [62]
For most patients with mild or moderate CSD, only conservative symptomatic treatment is recommended because the disease is self-limited. Administer antipyretics and analgesics as needed. Local heat may be applied to the involved lymph nodes.
Occasionally, lymph node aspiration is indicated for pain relief in patients with tender, fluctuant nodes. Use of antibiotics is controversial and not indicated for typical CSD in immunocompetent patients.
The role of corticosteroids in atypical CSD is somewhat controversial. Patients with neuroretinitis, encephalopathy with or without hemiplegia, and acute solid organ transplant rejection [63] have all been treated successfully with a combination of appropriate antibiotics and steroid therapy.
Antibiotic Treatment
Antibiotics are not indicated in most cases of CSD, but they may be considered for severe or systemic disease. Reduction of lymph node size has been demonstrated with a 5-day course of azithromycin [64] and may be considered in patients with severe, painful lymphadenopathy; however, no reduction in the duration of symptoms has been shown. Immunocompromised patients should be treated with antibiotics because they are particularly susceptible to systemic disease and bacteremia
Margileth et al reported the results of therapy for cat scratch antigen–proven CSD with 18 different antimicrobials in 268 adult and pediatric patients. [65] They concluded that the following 4 antibiotics were the most effective for patients with severe CSD:
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Rifampin - Efficacy of 87%
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Ciprofloxacin - Efficacy of 84%
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Gentamicin intramuscularly - Efficacy of 73%
-
Trimethoprim/sulfamethoxazole (TMP-SMZ) - Efficacy of 58%
These agents were considered moderately to highly effective, producing reduction or resolution of lymphadenopathy, a declining erythrocyte sedimentation rate, and decreased inflammatory and constitutional symptoms within 3-10 days. Severe disease was defined as persistent high fever (>103.1°F [>39.5˚C]) with severe systemic signs (eg, malaise, fatigue, blindness, headache) and lymphadenitis.
A prospective, randomized, double-blind, placebo-controlled study by Bass et al showed that azithromycin administered for 5 days decreased lymph node volume as measured by ultrasonography within the first month of treatment. No other differences in clinical outcome were noted. [64] Musso et al [66] found that aminoglycosides were bactericidal and Ives et al [67] showed that clarithromycin and azithromycin were efficacious in CSD. (See Table 3, below.)
Table 3. Response to Medications (Open Table in a new window)
Ciprofloxacin 500 PO bid |
Case Report 5 adults |
"Dramatic improvement" in a few days; defined as resolution of symptoms (ie, malaise and pain) |
Holley [68] |
Gentamicin 5 mg/kg/d IV/IM |
Case Report 3 febrile children; 2 with hepatitis, 1 with painful regional lymphadenopathy |
Resolution of fever and systemic symptoms in 1-2 days |
Bogue et al [69] |
TMP-SMZ 6-8 mg TMP/kg/d PO |
Uncontrolled retrospective study 60 patients with prolonged fever and systemic symptoms |
58% effective, 7-day course (see above) |
Margileth [48] |
Rifampin 10-20 mg/kg/d PO/IV |
Uncontrolled retrospective study 60 patients with prolonged fever and systemic symptoms |
87% effective, 7- to 14-day course (see above) |
Margileth [65] |
Azithromycin 500 mg PO qd for 1 day, then 250 mg PO qd for 4 days |
Prospective placebo-controlled, double-blind study 29 patients |
80% of lymph node volume (as measured by ultrasonography) resolved in 30 days in 7 of 15 patients on azithromycin vs 1 of 15 control patients |
Bass et al [64] |
Although data are lacking, patients with cat scratch disease 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.
Somewhat paradoxically, patients with AIDS and bacillary angiomatosis-peliosis frequently respond to a variety of commonly used antibiotics. Response to erythromycin, isoniazid, rifampin, doxycycline, and ethambutol is reported by Koehler et al. [70, 71] If an immunocompromised patient has treatment relapse, then prolonged treatment (4-6 mo) is recommended, although this is based on anecdotal data.
Bartonella henselae is generally resistant to penicillin, amoxicillin, and nafcillin.
Patients with neurologic bacillary angiomatosis or ocular manifestations have improved with antibiotic therapy and supportive care or with supportive care alone. In patients with thoracic and/or pulmonary disease, especially in association with prolonged fever and systemic symptoms, a trial of oral TMP-SMZ, ciprofloxacin, or azithromycin 2-3 times daily for 7-21 days is recommended. In the rare case of a severely ill patient, intramuscular gentamicin 5 mg/kg/d may be effective within 72 hours; continue treatment for 6-8 weeks.
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.
Importantly, because of the potential risk of arthropathy, caution should be used if considering the use of fluoroquinolones in patients younger than 18 years. Ciprofloxacin is not approved for administration in children. Additional adverse effects include gastrointestinal symptoms, dizziness, rash, seizures, headache, confusion, and tremors.
TMP-SMZ doses can include 8-12 mg/kg/d orally of TMP and 40-60 mg/kg/d orally of SMX every 12 hours. TMP-SMZ 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. Aminoglycoside therapy is recommended for endocarditis.
Treatment of Lymph Node Suppuration
If suppuration occurs, lymph node aspiration may be required. Aspiration of suppurating nodes is both a diagnostic and therapeutic procedure. Repeated aspirations may be performed if pus reaccumulates and pain recurs.
Treat recurrence of suppuration by incision and drainage. Although incision and drainage has been discouraged because it leaves a scar and may result in a draining fistula, the risk of fistulous sinus tract formation is small. This has been reported only in cases of atypical mycobacterial lymphadenopathy mistaken for CSD.
Surgical excision of an enlarged node is indicated when the diagnosis is in question or when repeated aspirations fail to relieve the patient's pain. Excision of a persistent ocular granuloma may be required.
Follow-up
Immunocompetent patients and immunocompromised patients without evidence of systemic disease may be followed on an outpatient basis. Depending on severity, immunocompromised patients or patients with atypical manifestations of CSD may require hospitalization. If admission is required, frequent monitoring of the adenitis is indicated to evaluate for suppurative complications.
Outpatients should be instructed to return for a follow-up evaluation to ensure resolution of lymphadenopathy in 2-4 months. Patients should return to care sooner if their condition worsens or the lymph node starts to suppurate. Closely follow up patients for 6 months or until the lymphadenopathy resolves.
Neurologic complications can occur up to 6 weeks after inoculation. Instruct parents to seek medical attention if they notice any abnormal behavior in their children.
If the lymphadenitis does not resolve or if it progressively enlarges, surgical biopsy may be indicated to rule out neoplastic causes and to definitively diagnose cat scratch disease.
Deterrence/Prevention
Pet quarantine, disposal, or euthanasia is unnecessary. The ability of the animal to transmit the organism is transient.
Although doxycycline treatment of cats is associated with decreased B henselae bacteremia, this treatment has not been shown to reduce the risk of cat-to-human transmission.
The natural history of feline infection and infectivity remains unknown. Feline B henselae bacteremia has been reported to last from weeks to months, with 100-fold fluctuations in bacteremic levels and intermittent negative cultures.
Given the established link between flea infection and B henselae transmission, common sense measures seem prudent (eg, avoiding stray cats, keeping pets free of fleas).
Children should be taught how to handle pets gently. Any scratch or bite, especially from a kitten, should be brought to the attention of parents and carefully followed up.
Consultations
Emergent consultation is not usually required for those with cat scratch disease. Consider emergent or outpatient consultation in cases of diagnostic uncertainty or with specific organ system involvement as indicated.
Consultation with an infectious disease specialist should be sought in cases of atypical cat scratch disease or in cases of cat scratch disease in immunocompromised patients. Consultation with a neurologist is indicated for patients with CNS involvement, and evaluation with an ophthalmologist may be needed in patients with any visual changes.
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Papulopustular lesions of a primary inoculation site on the hand of a 16-year-old patient. These lesions had been present for approximately 3 weeks. A cat scratch antigen skin test was positive with 15-mm induration. No treatment was administered, and her condition resolved spontaneously in 2.5 months. Courtesy of Andrew Margileth, MD.
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A crusted primary inoculation papule on the neck of a 4-year-old child. Note the adjacent lymphadenitis. This patient had contact with cats and had multiple scratches. Courtesy of Andrew Margileth, MD.
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This 13-year-old girl developed fatigue and malaise after being licked and scratched by a cat. The typical conjunctival granuloma was accompanied by a parotid mass and intraparotid adenitis. No treatment was administered, and all her signs and symptoms resolved in 3 months. Courtesy of Andrew Margileth, MD.
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This 9-year-old boy developed cat scratch disease (CSD) encephalitis and a papular pruritic dermatitis after sustaining cat scratches and developing regional lymphadenitis. He was in a coma for 4 days, but experienced a complete and rapid recovery within 3 weeks. Biopsy of the skin rash revealed nonspecific changes. The CSD antigen skin test result was positive. Courtesy of Andrew Margileth, MD.
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This 2.5-year-old boy was recovering from cat scratch disease acquired 10 months before when he developed this neck abscess over a period of 3 weeks. Biopsy revealed caseating granulomas; acid-fast bacillus and Warthin-Starry stain results were negative. Courtesy of Andrew Margileth, MD.
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This 10-year-old child had contact with dogs, but not cats. The impressive lymphadenitis had been present for 5 weeks and was not tender. Pathologic examination of a biopsy specimen of the lymph node revealed nonspecific changes. She had a positive cat scratch disease skin test result and negative purified protein derivative skin test results. Treatment with cephalexin was administered with a good response. Complete resolution occurred in 4.5 months. Courtesy of Andrew Margileth, MD.
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Warthin-Starry stained sections of lymph node showing chains and clusters of organisms. Courtesy of Andrew Margileth, MD.
Tables
Sign or Symptom |
Percentage, % |
Average Duration, d |
Adenopathy |
100 |
14-180 |
Adenopathy only |
52 |
14-180 |
Inoculation site |
59-93 |
7 |
Fever >101°F (38.3°C) |
32-60 |
6 |
Malaise/fatigue |
29 |
13 |
Headache |
13 |
4 |
Anorexia, weight loss, emesis |
14 |
5 |
Splenomegaly |
12 |
11 |
Sore throat |
5 |
2 |
Rash |
5 |
8.5 |
Parotid swelling |
2 |
- |
Conjunctivitis |
4.5 |
- |
Clinical Feature |
Margileth, n = 1174, % |
Carithers, n = 1200, % |
Typical presentation |
88.4 |
95 |
Inoculation lesion (skin, eye, mucous membrane) |
58.6 |
|
Unusual presentation |
11.6 |
5 |
Parinaud oculoglandular syndrome |
6.3 |
4 |
Encephalopathy |
2.3 |
0.25 |
Systemic disease, severe, chronic |
2 |
|
Erythema nodosum |
0.6 |
0.42 |
Atypical pneumonia |
0.2 |
|
Breast tumor |
0.2 |
|
Thrombocytopenic purpura |
0.1 |
0.08 |
Ciprofloxacin 500 PO bid |
Case Report 5 adults |
"Dramatic improvement" in a few days; defined as resolution of symptoms (ie, malaise and pain) |
Holley [68] |
Gentamicin 5 mg/kg/d IV/IM |
Case Report 3 febrile children; 2 with hepatitis, 1 with painful regional lymphadenopathy |
Resolution of fever and systemic symptoms in 1-2 days |
Bogue et al [69] |
TMP-SMZ 6-8 mg TMP/kg/d PO |
Uncontrolled retrospective study 60 patients with prolonged fever and systemic symptoms |
58% effective, 7-day course (see above) |
Margileth [48] |
Rifampin 10-20 mg/kg/d PO/IV |
Uncontrolled retrospective study 60 patients with prolonged fever and systemic symptoms |
87% effective, 7- to 14-day course (see above) |
Margileth [65] |
Azithromycin 500 mg PO qd for 1 day, then 250 mg PO qd for 4 days |
Prospective placebo-controlled, double-blind study 29 patients |
80% of lymph node volume (as measured by ultrasonography) resolved in 30 days in 7 of 15 patients on azithromycin vs 1 of 15 control patients |
Bass et al [64] |
