대한흉부영상의학회 Weekly Chest Cases

Case No : 1042 Date 2017-10-16

Courtesy of Mi Jung Park, MD / Gyeongsang National University
Age/Sex 45 / F
Chief Complaintfever for 1 week, occupation: farmer

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Diagnosis With Brief Discussion

Diagnosis: Scrub typhus (tsutsugamushi disease)
Radiologic Findings: Initial chest PA shows mild interstitial thickening in both lungs. Blunting of bilateral costophrenic angles is also noted.
Lung setting of the chest CT images shows interlobular septal thickening and subtle ground-glass opacities, which is compatible with interstitial pneumonia. Mediastinal setting of chest CT images shows enlargement of both axillary and right paratracheal lymph nodes. Small amounts of bilateral pleural effusions are seen.

An eschar was found in her right ankle. Laboratory data of the patient showed positive result for O. tsutsugamushi antibody, leukocytosis, and increased values of liver function tests, lactate dehydrogenase, and C-reactive protein.
Brief Review: Scrub typhus (tsutsugamushi disease) is an acute febrile illness caused by Orientia tsutsugamushi, characterized by focal or disseminated vasculitis and perivasculitis, which may involve the lungs, heart, liver, spleen, and central nervous system. Scrub typhus has epidemics in the late fall that affects a wide area of South-East Asia and the Pacific rim, including the Korean Peninsula. It is transmitted to humans by the bite of mites or chiggers.
The diagnosis of scrub typhus is based on history of exposure, clinical features, and serological testing. The main clinical manifestations are high fever, skin rash, myalgia, lymph node enlargement, and characteristic eschar formation at the site of chigger feeding. The clinical course is usually mild and self-limited with spontaneous recovery after a few days, but some patients have a more severe course which may be fatal.
The radiological findings of scrub typhus are variable, ranging from normal to fulminant pulmonary edema. On chest radiography, bilateral diffuse areas of reticulonodular opacity, hilar lymph node enlargement, and septal lines are the most common findings. Airspace consolidation is relatively uncommon and generally appears in the lower zone of both lungs. Unilateral or bilateral pleural effusion is common, found in 12-43% of patients. On high-resolution CT, interlobular septal thickening, axial interstitial thickening, ground-glass opacity, and centriloular nodules with lower lung predilection are common findings. Consolidation and large nodules are less common. CT findings of scrub typhus may reflect cellular infiltration, edema, and hemorrhage caused by vasculitis or may be due to interstitial edema secondary to cardiac involvement.
The differential diagnosis of scrub typhus is pulmonary interstitial edema and pulmonary interstitial pneumonia, such as viral pneumonia, Mycoplasma pneumonia, and Pneumocystis Jiroveci pneumonia, etc.
References: 1. Choi YH, Kim SJ, Lee JY, Pai HJ, Lee KY, Lee YS. Scrub typhus: radiological and clinical findings. Clin Radiol 2000; 55:140-144.
2. Jeong YJ, Kim S, Wook YD, Lee JW, Kim KI, Lee SH. Scrub typhus: clinical, pathologic, and imaging findings. Radiographics 2007; 27:161-172.
Please refer to: Case 854 Case 732 Case 635 Case 473
Keywords: Lung, Infection, Bacterial infection,

No. of Applicants : 73

▶ Correct Answer : 32/73, 43.8%

- Showa university Northern Yokohama Hospital , Japan KOTA WATANABE
- Showa University Fujigaoka Hospital , Japan KYOKO NAGAI
- Higashi-Ohmi General Medical Center , Japan AKITOSHI INOUE
- The University of Tokyo Hospital , Japan Yusuke Watanabe
- Kyeongpook National University Hospital , Korea (South) CHUNGEUN LIM
- Other , Korea (South) SEONG SU KANG
- Asan Medical Center , Korea (South) HYUN JUNG KOO
- , Korea (South) JIN YOUNG LEE
- Busan National University Hospital , Korea (South) LEE YOU JIN
- Oita University, Faculty of Medicine , Japan Fumito Okada
- Samsung Medical Center , Korea (South) JUHYUN KIM
- Onomichi municipal hospital , Japan Hirofumi Mifune
- The University of Tokyo Hospital , Japan TOSHIHIRO FURUTA
- Yonsei University, Wonju Severance Christian Hospital , Korea (South) JUYEON LEE
- Gifu University Hospital , Japan Yo Kaneko
- Samsung Medical Center , Korea (South) MIN YEONG KIM
- Dong-A University, College of Medicine , Korea (South) KI-NAM LEE
- 怨紐 , Korea (South) jin young kim
- University of Tsukuba Hospital , Japan HIROAKI TAKAHASHI
- Mallinckrodt Institute of Radiology , United States Naganathan BS Mani
- Diskapi Yildirim Beyazit Hospital, Ankara , Turkey MERIC TUZUN
- Other , Korea (South) HAYEON LEE
- Chonbuk National University Hospital , Korea (South) KUM JU CHAE
- Yonsei University College of Medicine, Shinchon Severance hospital , Korea (South) Young Joo Suh
- Ajou University Hospital , Korea (South) SEULGI YOU
- Katoh-gazou-shindan , Japan SHOICHI KATOH
- Teikyo University Hospital , Japan KAORU SUMIDA
- Ichinomiya Nishi Hospital , Japan Takao Kiguchi
- University of Tsukuba , Japan Toshitaka Ishiguro
- Pusan national university hospital , Korea (South) Jin Joo Kim
- the first affiliatited hospital of nanjing medical univercity , China HAI XU
- Ewha Womans University Hospital , Korea (South) YOOKYUNG KIM

▶ Correct Answer as Differential Diagnosis : 1/73, 1.4%

- University of Tsukuba, Dept of Radiology , Japan MANABU MINAMI

▶ Semi-Correct Answer : 1/73, 1.4%

- Amagasaki General Medical Center , Japan GENKI FUKUMOTO

대한흉부영상의학회 Korean Society of Thoracic Radiology

Archive of Old Cases

Case No : 1042 Date 2017-10-16

Discussion

No. of Applicants : 73