cat - scratch   disease ( csd ) is a zoonotic infection caused by the bacillus bartonella    henselae , which can be transmitted to humans after contact with infected cats .
typical presentation is characterized by a primary lesion ( papule ) at the site of inoculation ( cat scratch or bite ) followed by the development of regional painful and/or suppurative lymphadenopathy that is , occasionally , associated to systemic symptoms ( fever , discomfort , etc . ) and tends to have spontaneous resolution in a few weeks [ 1 , 2 ] .   atypical presentations or disseminated infection , except for immunosuppression , are exceptional , even though cases showing neurological manifestations ( encephalitis , facial paralysis , transverse myelitis , etc . ) , ophthalmologic complications , hepatosplenic granuloma , osteomyelitis , endocarditis , prolonged fever , and so forth , have been described ; in these cases , diagnostic suspicion and immediate antibiotic therapy are fundamental   [ 38 ]
. we present a case of unilateral neuroretinitis associated to bartonella henselae infection in a teenager with optimal response to antibiotic treatment .
a 13.7-year - old patient was admitted to the emergency department because of vision loss  starting seven days before admission , ocular pain , and photopsia in the left eye .
symptoms were sudden ( at the time she was doing a school test ) and coincided with an upper respiratory tract infection with fever in the previous 2 - 3 days .
personal history : asthma ( allergy to dust mites , pollen , and animal epithelium ) and strabismus / astigmatismus .
familiar history :   she has a sister suffering from idiopathic partial epilepsy , a paternal uncle who suffered a cerebral infarction ( cerebral aneurysm ) , a paternal aunt suffering from multiple sclerosis , and a maternal grandfather who suffered a cerebral stroke .
ophthalmologic examination revealed a decrease of visual acuity in the left eye ( right eye = 0.9 , left eye = 0.3 ) , disc swelling and macular star exudates with detachment of neuroepithelium ( figure 1 ) , and central scotoma in campimetry .
blood analysis showed leukocytosis and neutrophilia and an increase of erythrocyte sedimentation rate ( esr = 72  mm ) and c - reactive protein ( crp = 12  mg / dl ) .
biochemistry , proteinogram , coagulation , immunological , antinuclear antibodies , and rheumatoid factor studies were normal .  
pressure ( 170  mmh2o ) , leukocyte count , and protein and glucose in cerebrospinal fluid ( csf ) results were normal , and monoclonal bands were not detected .
serological studies ( hsv - i , hsv - ii , adenovirus , cmv , ebv , vih , vdrl , mycoplasma pneumoniae , rickettsia conorii , borrelia burdoferi , and toxoplasma ) were also negative , except for antibodies titer to bartonella henselae ( indirect immunofluorescence , ( ifi ) ) : igm 1/80 ( positive  >  1/10 ) and igg 1/800 ( positive >  1/100 ) .
visual evoked potential test showed an increase in latency and a decrease in amplitude in the left eye .
auditory and somatosensory evoked potential tests were normal . 
 progression . on initial findings ( neutrophilia and increase in acute - phase reactants ) antibiotic therapy with cefotaxime
several days later ( negative bacteriology , visual evoked potential alteration , and normal neuroimaging ) oral prednisone was added to her treatment ( 80  mg/24 hours , 10 days ) , and after clinical and epidemiological suspicion of neuroretinitis associated to cat - scratch disease ( serology was still unknown ) , treatment with cefotaxime was ended , and rifampicin ( 300  mg/12 hours ) and doxycycline ( 100  mg/12 hours ) were prescribed .  
the patient remained hospitalized for   15 days , and , by the time of discharge , retinography image and visual acuity had improved ( left eye = 0.6 ) , visual evoked potential tests were normal , and antibody titers to bartonella henselae had increased ( igg = 1/1600 ) .
after six weeks of antibiotic therapy , ophthalmologic exploration was completely normal , and visual acuity had recovered ( left eye = 0.9 , right eye = 0.9 ) .

 bartonella henselae infection is usually a self - limited and oligosymptomatic disease in immunocompromised patients .
it usually manifests as a regional painful lymphadenopathy preceded by an erythematous papule and/or pustule located in the place of a cat scratch or bite .
atypical presentations are quite variable in patients likely to be immunocompromised , and neuroretinitis associated with cat - scratch disease is not frequently seen [ 1 , 5 , 9 , 10 ] .
neuroretinitis usually appears a few weeks after typical symptoms of this pathology manifest , which many times goes unnoticed .
the main symptom is the abrupt unilateral loss of visual acuity although cases with bilateral affectation have been described [ 1113 ] .
the finding of disc swelling associated to macular star exudates , as it happened in this patient , is considered as a predictable sign of an ocular manifestation of cat - scratch disease [ 9 , 14 , 15 ] .
however , other etiologies should be discarded as a cause of optic neuropathy , such as arterial hypertension , diabetes mellitus , pseudotumor cerebri , syphilis , tuberculosis , toxoplasmosis , lyme disease , hiv , leptospirosis , and even multiple sclerosis and/or acute disseminated encephalomyelitis ( although the characteristic star exudates are not observed in demyelinating diseases [ 5 , 9 , 16 ] ) .  
other ophthalmologic findings related to bartonella henselae infection have been described , such as massive subretinal exudates , multifocal retinochoroiditis , diffuse retinal hemorrhages , vascular occlusive episodes , and necrotizing retinitis .
periodic ophthalmologic examination is mandatory in these cases [ 9 , 15 , 17 ] .
diagnostic suspicion in atypical presentations is difficult , above all in those cases in which there are not any presentations of skin lesions and/or lymphadenopathy , as did occur in this adolescent ; this could explain the possibility of delay in diagnosis and treatment [ 8 , 10 , 11 , 18 ] .  
diagnosis is mainly serological through enzyme immunoassays or indirect immunofluorescence with a high sensibility and specificity [ 10 , 11 , 15 , 1820 ] .
dna sequencing from gland tissue samples and visceral granulomas require invasive and expensive procedures . in this case
, diagnosis was accomplished through serological confirmation by indirect immunofluorescence of an increased igm antibody titer to bartonella henselae although a significant increase in igg antibodies titer was observed , enough to consider an acute infection by bartonella   sp .
since the disease is fairly benign , azithromycin prescription has been proposed exclusively in those patients with general symptoms or big and/or painful lymphadenopathies as well as immunocompromised patients .
nevertheless , antibiotic therapy is recommended in every patient with an atypical or disseminated presentation of neuroretinitis caused by bartonella henselae despite its evolution is usually benign .  
the possibility of ophthalmic irreversible structural lesions [ 5 , 17 , 18 , 21 , 22 ] suggests prescription of combined antibiotic therapy : rifampicin and doxycycline in patients older than eight and rifampicin with azithromycin or co - trimoxazole for patients below that age of   four to six weeks .   in this patient ,
antibiotic prescription was based upon clinical and epidemiological suspicion , and steroids were prescribed despite questionable usefulness [ 9 , 15 , 16 , 22 ] after the visual evoked potential test findings .
quick and complete recovery of ophthalmic symptoms experienced by this patient , in contrast to other cases referred to by the literature [ 11 , 12 , 18 ] , could be in relation to the prompt beginning of treatment . as a conclusion , cat - scratch disease with associated neuroretinitis is quite rare .
it should be suspected in any patient that manifests an abrupt loss of visual acuity together with the finding of disc swelling and macular star exudates .
 cat - scratch disease - related neuroretinitis is a relatively unusual pathology , with suspicious clinical epidemiological and serological diagnosis . 
 we present a case of an adolescent suffering from unilateral neuroretinitis associated with bartonella henselae infection characterized by abrupt loss of vision , optic disc swelling , and macular star exudates with optimal response to antibiotic treatment . 
1. Introduction
2. Case Report
3. Discussion