Cat Scratch Disease (Grand Rounds)

From EyeWiki
Original article contributed by: Sally Chang, MD
All contributors: Pooja Bhat MD and Vinay A. Shah M.D.
Assigned editor: Pooja Bhat MD
Review: Assigned status Up to Date by Pooja Bhat MD on August 29, 2018.

Cat Scratch Disease (Grand Rounds)

Financial Disclosure

Resident Grand Rounds Case

Sally Chang, M.D.

California Pacific Medical Center

  • Financial disclosures: none

Chief Complaint

  • "Seeing blurry spot in the right eye"

History of Present Illness:

  • JT is a 22 year old, Caucasian man who was healthy until 3 months ago when he started having flu-like symptoms including headache, high fever, and cough. He was diagnosed with mononucleosis and was not treated. Symptoms resolved after 2 months.
  • A week later, the patient started seeing a blurry spot temporal to his central vision in the right eye, which was stable for the past 3 weeks. He denied any eye pain.


Review of Systems:

  • Headache, high fever, and cough, which resolved 1 month ago. Never had lymphadenopathy.
  • No joint pain, no shortness of breath, no sexually transmitted disease

Medical history

  • Past Medical History: none
  • Allergies: NKDA
  • Medications: none
  • Social History: No smoking, alcohol, or illicit drug use. Lives in the San Francisco Bay Area, with recent camping trips around the Sierra mountains with no known tick bites


  • Vision: OD 20/25, OS 20/20
  • Pupils: reactive to light OU, no RAPD
  • Tonometry: OD 11, OS 13
  • Extraocular Motility: full OU
  • Visual Fields: full OU
  • External Exam: within normal limit OU
  • Slit Lamp Findings: Anterior segment normal OU
  • Dilated Fundus Exam Findings: see pictures

Fundus Examination

Fundus Photos

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  • Bilateral optic disc edema with disc hyperemia, worse in the right eye
  • Macular Edema extending from the optic nerve
  • Multiple punctate chorioretinitis throughout both fundi

Fluorescein Angiogram

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  • Staining of multiple punctate lesions and optic disc in both eyes

Optical Coherence Tomography

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Differential Diagnosis

  • What is the differential diagnosis for multifocal punctate chorioretinitis with disc involvement?
  • Infection
    • Syphilis
    • Tuberculosis
    • Lyme
    • Toxoplasmosis
    • Leptospirosis
    • Toxocariasis
    • Histoplasmosis
    • Coccidiodomycosis
    • Diffuse unilateral subacute neuroretinitis
  • Inflammation
    • Sarcoidosis
    • White dot syndrome
    • Punctate Inner Choroidopathy
  • Ischemia
    • Diabetic retinopathy
    • Hypertensive retinopathy
  • Malignancy / Metastases
  • Idiopathic

Laboratory Testing

  • CXR
  • PPD
  • RPR
  • Toxoplasmosis IgM and IgG titers
  • Monospot
  • HIV

All these tests were negative

  • B. Henselae IgM titer 1:80 (normal <1:20)
  • B. Henselae IgG titer >1:1024 (normal <1:64)

  • Patient got a kitten in 6/11
  • Flu-like symptoms started in 7/11-9/11
  • Eye symptoms started 10/11
  • Multiple cat scratches

Final Diagnosis

Cat scratch disease

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  • Worldwide zoonotic infection
  • Reservoir: asymptomatic bacteremia in domestic cats
  • Transmission to human: cat scratches, contamination of wounds
  • Mainly involve children and adolescents
  • Immunosuppressed people are at a higher risk

  • 24,000 cases in US annually
  • 2,000 hospital admissions in US annually
  • Higher incidence in the southern US, lower in the western US

  • Inoculation site: macule, papule, vesicle
  • Febrile prodrome
  • Regional lymphadenopathy
  • Disseminated disease

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Other Findings

Sally Chang Slide34.JPG

  • Intraretinal white spots
  • Branch retinal artery occlusions
  • Branch retinal vein occlusions
  • Vasculitis
  • Vitritis, pars planitis
  • Peripapillary angiomatosis


At least 3 of the 4 following:

  • History of cat exposure
  • Positive skin test to cat scratch disease antigen
  • Lymphadenopathy
  • Negative laboratory tests for other diseases

Sally Chang Slide37.JPG




  • No clear benefit with antibiotics, but may shorten duration
  • Adults: doxycycline, erythromycin, rifampin, azithromycin, or ciprofloxacin x 1 month
  • Children: azithromycin, bactrim


  • Antibiotics treatment is beneficial for 4 months
  • Erythromycin, doxycycline


  • Ocular complications of cat-scratch disease include Parinaud's oculoglandular syndrome, Leber's neuroretinitis, and focal chorioretinitis
  • Serologic testing is the best way to confirm diagnosis
  • Consider antibiotics treatment in all patients

Follow Up

  • After starting doxycycline 100mg BID, the patient's vision improved to 20/20 OU after 3 days.
  • He also developed macular star in the right eye after 2 weeks.
  • Multiple chorioretinitis became more pale and inactive.


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  • Ormerod LD, Dailey JP. Ocular manifestations of cat-scratch disease. Curr opin Ophthalmol 1999,10:209-216.
  • Cunningham ET, Koehler JE. Ocular bartonellosis. AJO 2000;130:340-349.
  • Purvin V, Sundarem S, Kawasaki A. Neuroretinitis: review of the literature and new observations. J Neuro-Ophthalmol 2011;31:58-68.
  • Chi SL, Stinnett S, Eggenberger E, et al. Clinical characteristics in 53 patients with cat scratch optic neuropathy. Ophthalmology 2011
  • Habot-Wilner Z, Zur D, Goldstein M, et al. Macular findings on optical coherence tomography in cat-scratch disease neuroretinitis. Eye 2011,25,1064-68.