Severe panuveitis – Uncommon presentation of cat scratch disease

Cat scratch disease (CSD), caused by Bartonella henselae, commonly presents with neuroretinitis characterized by optic disc edema and macular star. In this issue of the Oman Journal of Ophthalmology, there is an interesting case published by Che Mohd Hazidi et al.[1] of an unusual and severe posterior segment manifestation in a 7-year-old boy who developed rapidly progressive unilateral visual loss following a cat scratch injury to the right eye. Initial examination revealed severe panuveitis with dense vitritis, limiting fundus visualization. CSD is a zoonotic infection caused by B. henselae, typically transmitted through cat scratches, bites, or saliva contacting broken skin or mucous membranes.[2] While the most common ocular manifestation of CSD is neuroretinitis with optic disc edema and macular star,[3] a wide spectrum of posterior segment involvement has been reported, including retinal white spots, vasoproliferative lesions, papilledema, retinal vascular occlusions, vitreous inflammation, and chorioretinal lesions.[4] However, severe panuveitis associated with dense vitritis and diffuse choroidal thickening requiring surgical intervention is not common, making this case clinically significant. This case is notable because it highlights an uncommon and severe posterior segment manifestation of CSD characterized by dense vitritis and diffuse choroidal thickening leading to significant vision loss and necessitating pars plana vitrectomy. While neuroretinitis remains the most frequently reported ocular complication of Bartonella infection, this patient did not develop the classic macular star or neuroretinitis pattern. Instead, the predominant features were panuveitis, retinal vasculitis, optic disc edema, and marked vitreous inflammation, suggesting that ocular bartonellosis can involve the multiple layers of the eye and produce atypical inflammatory phenotypes.[5] The diffuse choroidal thickening observed on ultrasonography likely reflected severe inflammatory infiltration and vascular congestion of the choroid, contributing to visual impairment and mimicking conditions such as Vogt-Koyanagi-Harada (VKH) disease, posterior scleritis, or infectious endophthalmitis.[6] The diagnostic challenge in this case lies in the broad differential diagnosis of unilateral panuveitis with dense vitritis and choroidal thickening, which includes infectious etiologies such as tuberculosis, toxoplasmosis, viral retinitis, fungal endophthalmitis, as well as inflammatory conditions such as VKH disease, sarcoidosis, and sympathetic ophthalmitis. The absence of systemic signs, lack of serologic or imaging evidence for these conditions, and the presence of a clear history of cat scratch combined with positive Bartonella serology were critical in establishing the diagnosis. This emphasizes the importance of eliciting exposure history and maintaining a high index of suspicion for CSD in children presenting with unilateral ocular inflammation, particularly when posterior segment findings are predominant and disproportionate to anterior segment signs. In conclusion, this case expands the spectrum of ocular manifestations associated with CSD by demonstrating that Bartonella infection can present as severe unilateral panuveitis with dense vitritis and diffuse choroidal thickening, mimicking endophthalmitis and requiring surgical intervention. Prompt recognition, appropriate antimicrobial therapy, and judicious use of corticosteroids after infection control can lead to excellent visual recovery even in severe presentations. Clinicians should therefore consider CSD in the differential diagnosis of unilateral panuveitis, especially in pediatric patients with a history of cat exposure, as early diagnosis and treatment can significantly influence the visual prognosis. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal patient identity, but anonymity cannot be guaranteed.