Parinaud Oculoglandular Syndrome

Key points at a glance

Key Points at a Glance

• A syndrome characterized by unilateral granulomatous follicular conjunctivitis and ipsilateral regional lymphadenopathy
• The most common cause is cat scratch disease (Bartonella henselae), occurring in 5–7% of CSD patients
• Tularemia and sporotrichosis are also relatively common causative pathogens
• Diagnosis is made by Warthin-Starry silver stain or serological tests (IgM, IgG)
• Cat scratch disease is self-limiting and often resolves spontaneously within 1–2 months
• For persistent cases or immunocompromised patients, macrolide or tetracycline antibiotics are administered

1. What is Parinaud Oculoglandular Syndrome?

Parinaud oculoglandular syndrome (POGS) is a clinical syndrome characterized by unilateral granulomatous follicular conjunctivitis and ipsilateral regional lymphadenopathy (preauricular, parotid, submandibular, cervical) ¹.

The most common cause is cat scratch disease (CSD). CSD is a zoonotic infection caused by the gram-negative bacillus Bartonella henselae, which enters through cat scratches, bites, or flea bites. POGS occurs in 5–7% of CSD patients ^2,3. A retrospective study of ocular bartonellosis at a tertiary hospital in Malaysia found POGS in approximately 23% of confirmed cases, with a tendency to occur more often in younger individuals ².

Although many microorganisms can cause this syndrome, the majority are due to cat scratch disease, and the prognosis is generally good. Both systemic and ocular lesions often resolve spontaneously within 1–2 months ^1,3.

Q How does cat scratch disease infect the eye?

A

B. henselae is mainly transmitted through “hand-to-eye contact” when a person touches their eye with a hand that has been scratched by a cat. Direct infection from a cat scratch is rare in the oculoglandular form. Aerosolized cat flea feces have also been proposed as a route of transmission.

2. Main Symptoms and Clinical Findings

Subjective Symptoms

• Hyperemia and discharge: Accompanied by small to large amounts of serous or mucoid discharge
• Lymph node swelling and tenderness: Painful swelling of preauricular, parotid, submandibular, and cervical lymph nodes
• Low-grade fever: May be present as a systemic symptom
• Pain: Often no pain is perceived

Clinical Findings

Conjunctival Findings

• Granulomatous follicular conjunctivitis: Unilateral. Granulomatous follicles are seen on the conjunctiva. A key finding of POGS
• Conjunctival granuloma/nodule: May be accompanied by conjunctival ulcer overlying the granuloma
• Conjunctival abscess/ulcer: Abscess or ulcer may be seen on the conjunctiva
• Periorbital edema: May be accompanied by mild edema

Lymph Node Findings

Painful swelling of ipsilateral preauricular, postauricular, submandibular, and cervical lymph nodes is characteristic¹. Younger patients tend to present with cervical lymphadenopathy, while those aged 15 years and older tend to have inguinal or axillary lymphadenopathy.

Ocular Complications of CSD

In addition to POGS, CSD can cause the following ocular complications:

• Neuroretinitis: Characterized by optic disc edema and a star figure (macular star). Differentiation from Leber idiopathic stellate neuroretinitis is necessary.
• Uveitis/Choroiditis
• Branch retinal artery occlusion
• Acute endophthalmitis

In ocular bartonellosis overall, small white retinal lesions are the most common (82.6%), followed by neuroretinitis (47.8%)².

3. Causes and Risk Factors

Causative Pathogens

Cat scratch disease (most common)

Pathogen: Bartonella henselae (gram-negative bacillus)

Vector: Cats (especially kittens), dogs, cat fleas, sand flies

Incubation period: 3 days to 3 weeks

Tularemia

Pathogen: Francisella tularensis (gram-negative coccobacillus)

Vector: Rabbits, squirrels, ticks, mosquitoes

Incubation period: 2–5 days (rarely up to 3 weeks)⁴

Sporotrichosis

Pathogen: Sporothrix schenckii (dimorphic fungus)

Source of infection: Soil, plant organic matter, infected animals

Endemic areas: Tropical and subtropical regions such as Brazil and Peru⁵

Other causes include tuberculosis, syphilis, coccidioidomycosis, sarcoidosis, herpes simplex, chancroid, leprosy, listeriosis, mumps, etc.

Risk Factors

• Contact with cats: Can develop even without scratches or bites. Common in children and veterinarians
• Outdoor activities: Hunters, campers, and meat handlers have a high risk of tularemia
• Gardening/Agriculture: Contact with soil and plants poses a risk of sporotrichosis
• Immunocompromised: HIV-infected individuals are more prone to severe disease

Prevention and Daily Care

If you own a cat, clean any scratches or bites immediately. Avoid rubbing your eyes with hands that have touched cats. Since kittens have a high flea carriage rate, regular flea control is recommended.

Q Will I definitely get infected if I own a cat?

A

Simply owning a cat does not cause infection. Direct contact such as being scratched by a cat carrying B. henselae is necessary. Kittens have a high carriage rate, and fleas are vectors, so regular flea control is an effective preventive measure.

4. Diagnosis and Testing Methods

Parinaud Oculoglandular Syndrome image

Michele Shi-Ying Tey, Gayathri Govindasamy, Francesca Martina Vendargon The clinical spectrum of ocular bartonellosis: a retrospective study at a tertiary centre in Malaysia 2020 Nov 16 J Ophthalmic Inflamm Infect. 2020 Nov 16; 10:31 Figure 5. PMCID: PMC7667203. License: CC BY.

A photograph showing a localized granuloma on the upper tarsal conjunctiva with surrounding papillary reaction. The granulomatous lesion with conjunctival congestion represents the local findings of Parinaud oculoglandular syndrome.

History Taking

Inquiry about animal contact (cats, dogs, rabbits, ticks), outdoor activities, travel history, and occupational history is most important.

Diagnostic Methods by Cause

Cause	Recommended Test	Diagnostic Criteria
Cat scratch disease	Serology (IgM, IgG)	IgM ≥ 1:20, IgG ≥ 1:256
Tularemia	Serology	Titer > 1:128 suggests infection
Sporotrichosis	Culture (Sabouraud agar)	Identification of fungus

Diagnosis of Cat Scratch Disease

• Serological testing: Most commonly used. IgM titer ≥1:20 or IgG titer ≥1:256 by indirect immunofluorescence assay suggests active infection ³. IgG titer ≥1:512 strongly suggests recent infection. A four-fold rise in IgG titer between acute and convalescent phases is confirmatory.
• Warthin-Starry silver stain: B. henselae in conjunctival scrapings stains brown. Steiner silver stain or Brown-Hopp stain can also be used on biopsy tissue.
• PCR: Excellent sensitivity and specificity, but culture is difficult and time-consuming.
• General tests: Check erythrocyte sedimentation rate, C-reactive protein, and syphilis serology.

Differential Diagnosis

• Adenoviral conjunctivitis: Presents with follicular conjunctivitis but does not form granulomas.
• Tuberculous conjunctivitis: Chronic granulomatous inflammation. Differentiate with tuberculin skin test or IGRA.
• Syphilitic conjunctivitis: Diagnosed by syphilis serology (lipid antigen test and treponemal antigen test).

5. Standard Treatment

Cat Scratch Disease

CSD is a self-limiting disease, and treatment is primarily supportive.

• Mild cases: Observation and broad-spectrum antibiotic eye drops to prevent secondary infection. Spontaneous resolution occurs over several weeks.
• Moderate to severe cases and immunocompromised patients: Systemic antibiotic therapy is administered.
  • Azithromycin: A macrolide antibiotic, easy to use in children. In a randomized, double-blind, placebo-controlled trial by Bass et al., a 5-day course resulted in a significant reduction in lymph node volume by 80% within the first 30 days (7 of 14 in the treatment group vs. 1 of 15 in the placebo group) ⁶.
  • Doxycycline: Tetracycline class. One of the first-line options for adults.
  • Trimethoprim/Sulfamethoxazole: Used as combination therapy.
  • Ciprofloxacin: Fluoroquinolone class.
  • Rifampin: Used in combination for severe cases.
• Treatment duration is individualized based on the patient’s clinical course.

Tularemia

• Severe cases: Administer streptomycin or gentamicin for 7–14 days.
• Mild cases: Administer doxycycline or ciprofloxacin for 14–21 days. Beta-lactams are considered ineffective, and fluoroquinolones are recommended as first-line therapy⁴.
• Local treatment: Ciprofloxacin eye drops or tobramycin eye drops/ointment.

Sporotrichosis

• Systemic treatment: Oral itraconazole is first-line⁵. Potassium iodide is also effective.
• Local treatment: Topical administration of fluconazole eye drops.
• Treatment duration is usually several weeks to several months.

Treatment Precautions

CSD resolves spontaneously in most cases, so excessive antibiotic administration is unnecessary. However, in immunocompromised patients, there is a risk of disseminated infection, so prompt systemic antibiotic therapy should be initiated. Tularemia can become severe if treatment is delayed, so empirical therapy should be started when suspected.

Q Does cat scratch disease heal without treatment?

A

POGS due to cat scratch disease is self-limiting, and in immunocompetent patients it often resolves spontaneously within 1–2 months. However, disappearance of granulomas may take several weeks, and lymphadenopathy may take several months to resolve. In prolonged cases, antibiotic therapy may be considered.

6. Pathophysiology and Detailed Pathogenesis

Pathology of Cat Scratch Disease

B. henselae is a Gram-negative small bacillus that is a fastidious obligate intracellular bacterium. The bacteria enter through cat scratches or bites and form a red papule (primary lesion) at the inoculation site 1–2 weeks after injury. After another 1–2 weeks, swelling and tenderness of the regional lymph nodes appear.

Ocular infection mainly occurs through hand-to-eye contact with contaminated hands. B. henselae reaching the conjunctiva proliferates beneath the conjunctival epithelium and induces a granulomatous inflammatory response. Inflammation spreads to the ipsilateral regional lymph nodes (preauricular, parotid, submandibular), causing painful lymphadenopathy.

Neurotransmitters related to corneal innervation (such as substance P and CGRP) are not major factors in this disease; direct bacterial invasion and the host cell-mediated immune response are central to the pathology.

Pathology of Neuroretinitis

In neuroretinitis associated with CSD, edema extending from the optic disc to the macula occurs, and a characteristic star figure (macular star) appears. Hematogenous dissemination of B. henselae is thought to cause direct bacterial invasion of the optic nerve and retina.

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8. References

1. Dixon MK, Dayton CL, Anstead GM. Parinaud’s Oculoglandular Syndrome: A Case in an Adult with Flea-Borne Typhus and a Review. Tropical Medicine and Infectious Disease. 2020;5(3):126. PMID: 32751142. PMCID: PMC7558689.

2. Tey MS, Govindasamy G, Vendargon FM. The clinical spectrum of ocular bartonellosis: a retrospective study at a tertiary centre in Malaysia. Journal of Ophthalmic Inflammation and Infection. 2020;10:31. PMID: 33191467. PMCID: PMC7667203.

3. Sabir S, Daley SF, Huang B. Cat Scratch Disease. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025. Bookshelf ID: NBK482139.

4. Nagy KI, Pribelszki E, Sira Á, Fullajtár B, Rácz T, Major T. Francisella tularensis Infection Causing Parinaud Oculoglandular Syndrome. The American Journal of Case Reports. 2024;25:e944321. PMID: 38941282. PMCID: PMC11332965.

5. Ferreira CP, Nery JAC, de Almeida ACO, Ferreira LC, Corte-Real S, Conceição-Silva F. Parinaud’s oculoglandular syndrome associated with Sporothrix schenckii. IDCases. 2014;1(3):38–39. PMID: 26955523. PMCID: PMC4762793.

6. Bass JW, Freitas BC, Freitas AD, et al. Prospective randomized double blind placebo-controlled evaluation of azithromycin for treatment of cat-scratch disease. Pediatric Infectious Disease Journal. 1998;17(6):447–452. PMID: 9655532.