A 75-year-old woman was referred to the oral surgery clinic for a suspected dental infection. Her medical history included tuberculosis, hypertension, hyperlipidemia, and neurogenic bladder. Her surgical history included hip joint surgery at the ages of 11, 27, and 68 years. Four weeks earlier, the patient visited an otolaryngologist for otorrhea of the right ear and was diagnosed with otitis media and treated with antibiotics. On the same day, the patient underwent extraction of the right mandibular canine and lateral incisor by the patient's family dentist. Two weeks earlier, the patient had visited the primary care doctor for regular follow-up and complained of fatigue, fever, dysgeusia, swelling and numbness of the neck, and backache, which continued after the extraction. On laboratory examination, C-reactive protein (CRP) was 11.46 mg/dL, and the white blood cell count was 11,000/muL. Subsequently, chest X-ray and computed tomography (CT) showed no abnormal findings, and she tested negative for influenza virus. The patient then developed trismus and pain at the apex of the tongue and was referred to the oral surgery clinic.
On examination, the patient complained of fever and discomfort of the tongue with dysgeusia. Although usually both the maxilla and mandible cause dentures to wear, this does not occur when the teeth have been extracted. Salivary function was relatively good, and there was no xerostomia observed. No trismus was found; the teeth extraction sockets had healed well. None of the other residual teeth exhibited any prominent caries or periodontal disease. There were no abnormal findings in the orofacial region except for the dysgeusia and redness and numbness at the apex of the tongue (Figure 1). Orthopantomography revealed no abnormal findings, including maxillary sinuses and temporomandibular joints (Figure 2). On physical examination, the patient's temperature was 38.5 C, and blood pressure was 125/75 mmHg. The serum CRP concentration was 19.4 mg/dL, and the WBC count was 14,700/muL (Table 1). Given the history of tooth extraction, the patient was immediately referred to the division of cardiology for suspected IE.
The cardiologist took blood cultures, which were negative for bacteria, and an ultrasound cardiogram and transesophageal echocardiography showed neither clear vegetations nor regurgitation. For the remittent fever of more than 38.0 C, the patient was admitted to the cardiology clinic three days after the first visit and underwent a complete examination. Serum examination showed the following: PR3-ANCA < 1 IU/mL, MPO-ANCA 124.0 IU/mL, cytomegalovirus complement fixation test 8, ferritin 471 ng/mL, and CH50 60.0 U/mL. Sputum cultures, acid-fast bacterial cultures, and fecal cultures were negative. CT imaging showed no abnormal findings causing fever, and deep vein thrombosis was not found on ultrasonography of the veins of the lower extremities. There were no active symptoms related to the right otitis media other than depression of the eardrum on otolaryngological examination.
Fourteen days after the first visit, the patient was transferred to the Department of Rheumatology and Clinical Immunology because of the high suspicion of AAV, although renal dysfunction and findings of interstitial pneumonia were not evident. Twenty-seven days after the first visit, a renal biopsy was planned, but it was postponed due to influenza A infection. After the renal biopsy, which showed the findings of necrotizing glomerulonephritis, the patient was finally diagnosed with MPA (fever, MPO-ANCA-positive, CRP elevation, proteinuria, and histopathological findings of renal biopsy) 40 days after the first visit. Steroid therapy was then started with 30 mg prednisolone/day without immunosuppressive agents, and four days later, the patient was discharged. The inflammatory symptoms improved well, and the dysgeusia and numbness at the apex of the tongue disappeared four weeks later. At 20-week follow-up, prednisolone was tapered to 10 mg/day, and she was MPO-ANCA-negative.
The protocol of the report has been approved by the ethical review board of the university.