Which infectious agent causes cat-scratch fever, the most common cause of Parinaud's Oculoglandular Syndrome?

Which infectious agent causes cat-scratch fever, the most common cause of Parinaud's Oculoglandular Syndrome?

• A. Bartonella henselae
• B. Borrelia burgdorferi
• C. Mycobacterium leprae
• D. Streptococcus pyogenes

Answer: (A)

Parinaud's oculoglandular syndrome is driven by an infectious trigger that links conjunctival granulomatous inflammation with regional lymph node swelling on the same side of the face. The most common cause is cat-scratch disease, produced by Bartonella henselae. This organism is a small Gram-negative bacterium carried by cats and transmitted to humans after scratches or bites, often with flea involvement. When Bartonella henselae enters the conjunctiva, it provokes a localized granulomatous reaction in the eye and ipsilateral preauricular lymphadenopathy, which is the hallmark of this syndrome. The other organisms listed are associated with different diseases and not with this ocular presentation. Borrelia burgdorferi causes Lyme disease, Mycobacterium leprae causes leprosy, and Streptococcus pyogenes causes strep infections. None of these typically produce the cat-scratch–related ocular granulomatous conjunctivitis with concurrent lymphadenopathy seen in Parinaud's syndrome. Treatment is often supportive, with antibiotics like azithromycin used in many cases to hasten resolution.

Parinaud's oculoglandular syndrome is driven by an infectious trigger that links conjunctival granulomatous inflammation with regional lymph node swelling on the same side of the face. The most common cause is cat-scratch disease, produced by Bartonella henselae. This organism is a small Gram-negative bacterium carried by cats and transmitted to humans after scratches or bites, often with flea involvement. When Bartonella henselae enters the conjunctiva, it provokes a localized granulomatous reaction in the eye and ipsilateral preauricular lymphadenopathy, which is the hallmark of this syndrome.

The other organisms listed are associated with different diseases and not with this ocular presentation. Borrelia burgdorferi causes Lyme disease, Mycobacterium leprae causes leprosy, and Streptococcus pyogenes causes strep infections. None of these typically produce the cat-scratch–related ocular granulomatous conjunctivitis with concurrent lymphadenopathy seen in Parinaud's syndrome. Treatment is often supportive, with antibiotics like azithromycin used in many cases to hasten resolution.