[Cat scratch disease. Clinical study of 26 patients. Role and importance of PCR]

[Elbow abscess revealing cat-scratch disease: about a case]

Cat-scratch disease (CSD) is a common cause of chronic benign lymphadenopathy in the child and the young adult. Bartonella henselae is the agent responsible for this disease. Common symptoms include regional lymphadenopathy associated with fever. We report a clinically atypical and potentially misleading case of a 18-year old girl with CSD revealed by elbow abscess.

[Eye and cat scratch disease: A case series]

INTRODUCTION

Cat scratch disease is a pleiomorphic condition, sometimes with isolated ophthalmic involvement. We report the clinical observations of seven cases with ophthalmologic manifestations of cat scratch disease.

OBSERVATIONS

There were seven patients, with a median age of 52 years, of whom five were women and three had unilateral involvement. Six exhibited Leber's stellate neuroretinitis, an incomplete syndrome in two cases, and one associated with chorioretinal foci. One patient had isolated retinal infiltrates. The diagnosis of cat scratch disease was confirmed by Bartonella henselae serology, positive in all cases. All patients received treatment with doxycycline. Ocular complications (with optic atrophy and macular retinal pigment epithelial changes) were noted in five cases.

DISCUSSION

Ocular bartonellosis is an atypical clinical form. It requires a directed ancillary work-up with serology or PCR, which has the peculiarity of being highly specific if not very sensitive. Treatment is above all preventive. Antibiotics may be initiated.

CONCLUSION

Cat scratch disease must be excluded in the work-up of posterior uveitis.

[An uncommon cutaneous presentation of cat scratch disease]

BACKGROUND

Herein we report a case of cat scratch disease on account of its atypical presentation.

PATIENTS AND METHODS

A 21-year-old woman presented erythema nodosum associated with painful bilateral inguinal adenopathy, odynophagia, joint pain and evening urticaria in a setting of impaired general condition. Initial serological testing for Bartonella henselae was negative. PCR for Bartonella henselae performed on an adenectomy fragment was positive. A favourable outcome was achieved with azithromycin.

COMMENTS

This case shows an atypical and severe presentation of cat scratch disease and raises the problem of sensitivity of serotyping.

[The diagnosis of cat-scratch-disease-associated adenitis: diagnostic value of serology and polymerase chain reaction]

The diagnosis of cat scratch disease (CSD) associated adenitis relies classically on the association of clinical, epidemiological and bacteriological criteria. The polymerase chain reaction (PCR) looks like a more competitive diagnostic trial than serology. We evaluated the sensitivity, specificity and predictive positive and negative values of serology in routine diagnosis of CSD. A retrospective study over five years was led among patients presenting a suspicion of CSD and having a serology and/or a PCR. The Gold standard for diagnosis was PCR. The serological tests of Bartonella henselae was performed once in 482 patients, of which 2% (11 out of 482) were positive, and twice in only 39 patients (8%). The PCR diagnosis method for B. henselae was performed in biopsy of specimen lymph nodes in 28 patients and 14 out of 28 were positive. In nine patients, the diagnosis was exclusively made by PCR. Among the 14 patients whose PCR was negative, two had a positive serology and in three others patients, the serology was not performed. The sensitivity of serology was 35%, this confirms the low sensitivity of the serology in the CSD diagnosis. The diagnosis was confirmed in 56% of cases where PCR was performed. This led us to propose to perform systematically the PCR test for B. henselae in case of adenitis possibly associated with CSD.

Diagnosis of cat scratch disease with detection of Bartonella henselae by PCR: a study of patients with lymph node enlargement

Cat scratch disease (CSD) is mostly due to Bartonella henselae after inoculation of the organism through a skin injury. Since the causative bacteria cannot be easily cultured from human lymph node samples, the diagnosis usually relies on epidemiological, clinical, histological, and serological criteria (classical criteria). A study was performed to determine the diagnostic value of PCR analysis for the detection of B. henselae for the diagnosis of CSD and its place in the diagnostic strategy alongside the classical criteria. Over a 7-year period, lymph node biopsy specimens or cytopunctures from 70 patients were systematically tested by PCR for the presence of B. henselae DNA (htrA gene) in the Bacteriology Laboratory of the Hôpitaux Universitaires de Strasbourg. Serological testing by an immunofluorescence assay for B. henselae antibodies was also performed for each patient, and clinical, epidemiological, and histological data were collected. The patients were then divided into two groups according to the number of positive diagnostic criteria for CSD: 29 patients with definite CSD (two or more classical criteria) and 15 patients with possible CSD (less than two classical criteria). The remaining 26 patients for whom another diagnosis was retained were used as a control group. Among all criteria, PCR analysis had the best specificity (100%). The PCR assay for B. henselae was positive for 22 (76%; 95% confidence interval [CI95], 56.5 to 89.7%) of the 29 definite CSD patients and 3 (20%; CI95, 4.3 to 48.1%) of the 15 possible CSD patients. We then studied combinations of diagnostic criteria, including B. henselae PCR analysis. The best diagnostic performance was observed if at least two criteria were present among serologic, epidemiologic, histological, and molecular criteria.

Neurorétinite à Bartonella henselae : maladie des griffes du chat

We report a case of cat-scratch disease neuroretinitis for which systemic and ocular investigations proved the responsibility of Bartonella henselae. An 11-year-old boy was referred to the hospital in November 2002 for severe visual loss in the left eye over the preceding 2 weeks. At the same time, he also developed a flu-like illness. The best corrected acuity in the left eye was counting fingers at 30 cm. Posterior segment examination on the left eye showed an optic disk edema with papillary and peripapillary hemorrhages and serous retinal detachment, mild vitreous inflammation, and two little perivascular white spots. The medical history was unremarkable except for a cat scratch on his left forearm 2 months before. Four weeks of antibiotic therapy including oral rifampin and doxycycline was used. Bartonella henselae immunoglobulin M were first detected with Bartonella henselae immunoglobulin G testing negative at this time. A 3-week serum showed immunoglobulin M seroreversion, while Bartonella henselae immunoglobulin G appeared. Other causes of optic disk edema with macular star were excluded by biological data. Bartonella antibodies to both Bartonella henselae and Bartonella clarridgeiae were detected in the cat. Ophthalmic follow-up showed progressive resorption of the neuroretinitis and the visual acuity increased to 5/10. The significance of this case report lies in the reminder that this pathology can be the cause of neuroretinitis; the prognosis can be improved by earlier treatment.