Scrub typhus is an acute febrile disease caused by the intracellular organism Orientia tsutsugamushi. The main pathogenesis is focal or disseminated multi-organ
vasculitis caused by the
infection of endothelial cells and the perivascular infiltration of leukocytes. Many studies have reported
interstitial pneumonia,
cholecystitis,
pancreatitis, and
meningoencephalitis in
scrub typhus. However, there is no report about
sialoadenitis in a patient with
scrub typhus. A 79-year-old man was admitted to the emergency room due to a high
fever,
headache, and
myalgia.
Scrub typhus was confirmed based on the indirect immunofluorescence assay and the nested polymerase chain reaction. He suffered from severe dry mouth and underwent Tc-99m
pertechnetate salivary scintigraphy. While the radiopharmeceutical uptake of the bilateral parotid and submandibular glands was within normal range, salivary excretion into the oral cavity was markedly decreased. After the proper
antibiotic treatment, salivary scintigraphy was performed again. Radioactivity in the oral cavity was increased and the ejection fraction (%) after using sialogogue was also improved to the normal range. As far as we know, this is the first report to show salivary scintigraphy of a patient with
scrub typhus. By using a Tc-99m
pertechnetate salivary scintigraphy, we found that the excretory function of salivary glands was markedly decreased, while the uptake ability was preserved in
scrub typhus, unlike Sjögren's syndrome and radiation-induced
xerostomia. Salivary scintigraphy presents dry mouth objectively and provides quantitative values as well. Salivary scintigraphy could contribute to the assessment of
sialoadenitis before and
after treatment of
scrub typhus.