Parinaud's Oculoglandular Syndrome: A Case in an Adult with Flea-Borne Typhus and a Review

Francisella tularensis Infection Causing Parinaud Oculoglandular Syndrome

BACKGROUND Parinaud oculoglandular syndrome is a unilateral granulomatous palpebral conjunctivitis associated with preauricular, submandibular, and cervical lymphadenopathies. Several infectious diseases can cause Parinaud oculoglandular syndrome, usually with a conjunctival entry. The most common underlying pathology is cat scratch disease, followed by the oculoglandular form of tularemia. Diagnosis is usually a serious challenge as these infections are themselves rare. On the other hand, Parinaud oculoglandular syndrome may be a rare manifestation of more common disorders (eg, tuberculosis, syphilis, mumps, herpes simplex and Epstein-Barr virus, adenovirus, Rickettsia, Sporothrix, Chlamydia infections). CASE REPORT We present the case of a 66-year-old man with granulomatous conjunctivitis and ipsilateral preauricular, submandibular, and upper cervical lymphadenopathies following a superficial corneal injury. Although the systematic amoxicillin/clavulanic acid and metronidazole antibiotic therapy started immediately at admission, the suppuration of the lymph nodes required surgical drainage. Based on his anamnesis (sheep breeding; a twig scratching his eye 2 days before the initial attendance) and symptoms, a zoonosis, namely the oculoglandular form of tularemia, was suspected, empiric ciprofloxacin therapy was administered, and the patient recovered without sequelae. The Francisella tularensis infection was eventually confirmed by microagglutination serologic assay. CONCLUSIONS If Parinaud oculoglandular syndrome is diagnosed and cat scratch fever as the most common etiology is not likely, other zoonoses, especially the oculoglandular form of tularemia, should be suspected. Serology is the most common laboratory method of diagnosing tularemia. Empiric fluoroquinolone (ciprofloxacin) or aminoglycoside (gentamicin or streptomycin) antibiotic therapy should be started immediately at the slightest suspicion of oculoglandular tularemia.

Flea-Borne Typhus as a COVID-19 Mimic: A Report of Four Cases

Flea-borne typhus (FBT), due to Rickettsia typhi and R. felis, is an infection causing fever, headache, rash, hepatitis, thrombocytopenia, and diverse organ manifestations. Cough occurs in about 30% of patients with FBT, and chest X-ray abnormalities are seen in 17%. Severe pulmonary manifestations have also been reported in FBT, including adult respiratory distress syndrome and pulmonary embolism. Because of these pulmonary manifestations, FBT can mimic Coronavirus Illness 2019 (COVID-19), a febrile illness with prominent respiratory involvement. Flea-borne typhus and COVID-19 may also have similar laboratory abnormalities, including elevated ferritin, C-reactive protein, and D-dimer. However, elevated transaminase levels, rash, and thrombocytopenia are more common in FBT. Herein, we present four cases of patients with FBT who were initially suspected to have COVID-19. These cases illustrate the problem of availability bias, in which the clinician thinks a particular common condition (COVID-19 in this case) is more prevalent than it actually is.

Murine Typhus: A Review of a Reemerging Flea-Borne Rickettsiosis with Potential for Neurologic Manifestations and Sequalae

Murine typhus is an acute febrile illness caused by Rickettsia typhi, an obligately intracellular Gram-negative coccobacillus. Rats (Rattus species) and their fleas (Xenopsylla cheopis) serve as the reservoir and vector of R. typhi, respectively. Humans become infected when R. typhi-infected flea feces are rubbed into flea bite wounds or onto mucous membranes. The disease is endemic throughout much of the world, especially in tropical and subtropical seaboard regions where rats are common. Murine typhus is reemerging as an important cause of febrile illness in Texas and Southern California, where an alternate transmission cycle likely involves opossums (Didelphis virginiana) and cat fleas (Ctenocephalides felis). Although primarily an undifferentiated febrile illness, a range of neurologic manifestations may occur, especially when treatment is delayed. Serology is the mainstay of diagnostic testing, but confirmation usually requires demonstrating seroconversion or a fourfold increase in antibody titer from acute- and convalescent-phase sera (antibodies are seldom detectable in the first week of illness). Thus, early empiric treatment with doxycycline, the drug of choice, is imperative. The purpose of this review is to highlight murine typhus as an important emerging and reemerging infectious disease, review its neurologic manifestations, and discuss areas in need of further study.

Unilateral Conjunctivitis With Multifocal Granulomatous Lesions in a Child Aged 10 Years

This case report discusses a diagnosis of Parinaud oculoglandular syndrome in a child aged 10 years who presented with a granulomatous conjunctivitis in the left eye.

Vector-Borne Tularemia: A Re-Emerging Cause of Cervical Lymphadenopathy

Tularemia is a zoonosis caused by the highly invasive bacterium Francisella tularensis. It is transmitted to humans by direct contact with infected animals or by vectors, such as ticks, mosquitos, and flies. Even though it is well-known as a tick-borne disease, it is usually not immediately recognised after a tick bite. In Slovenia, tularemia is rare, with 1-3 cases reported annually; however, the incidence seems to be increasing. Ulceroglandular tularemia is one of its most common forms, with cervical colliquative lymphadenopathy as a frequent manifestation. The diagnosis of tularemia largely relies on epidemiological information, clinical examination, imaging, and molecular studies. Physicians should consider this disease a differential diagnosis for a neck mass, especially after a tick bite, as its management significantly differs from that of other causes. Tularemia-associated lymphadenitis is treated with antibiotics and surgical drainage of the colliquated lymph nodes. Additionally, tularemia should be noted for its potential use in bioterrorism on behalf of the causative agents' low infectious dose, possible aerosol formation, no effective vaccine at disposal, and the ability to produce severe disease. This article reviews the recent literature on tularemia and presents a case of an adult male with tick-borne cervical ulceroglandular tularemia.