Application of polymerase chain reaction assay in the diagnosis of orbital granuloma complicating atypical oculoglandular cat scratch disease.

BACKGROUND

Parinaud oculoglandular syndrome is uncommon. Most cases are caused by cat scratch disease (CSD), recently discovered to be associated with the pathogen Bartonella henselae. Before isolation of the micro-organism, diagnosis relied on the presence of characteristic clinical features. However, atypical cases could cause diagnostic problems. With the development of an indirect fluorescent antibody test and polymerase chain reaction (PCR) assay, oculoglandular CSD can be diagnosed readily.

METHODS

The authors report a case of atypical Parinaud oculoglandular syndrome in a 51-year-old woman who presented with an inferior conjunctival forniceal mass extending into anterior orbital tissues. Blood and operative tissue specimens were obtained for routine screening and histopathologic analysis but more specifically for serologic analysis, culture, and PCR assay for B. henselae. Computed tomography was performed to delineate the mass.

RESULTS

Cultures for B. henselae were negative. Initial serologic analysis demonstrated a low IgG response without detectable IgM, but 1 month later had undergone a fourfold rise in IgG, again without detectable IgM. Histopathologic analysis showed a nonspecific necrotizing granulomatous inflammation consistent with but not diagnostic of CSD. Polymerase chain reaction assay for B. henselae was strongly positive. Computed tomographic scan showed a preseptal and anterior orbital inflammatory process.

CONCLUSIONS

Cat scratch disease due to B. henselae should be suspected in patients with atypical conjunctival inflammation associated with regional lymphadenopathy. PCR assay is extremely useful in establishing the diagnosis. The PCR assay offers the additional advantage of early diagnosis because the test is positive early in the disease. Antibiotic therapy remains controversial. In this case, surgical excision hastened resolution of the conjunctival inflammation. However, the lymphadenopathy responded poorly to antibiotics.