Division of Infectious Disease, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi District, Bangkok, 10400, Thailand.
Division of Dermatology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
BMC Infect Dis. 2018 Sep 17;18(1):467. doi: 10.1186/s12879-018-3378-0.
Legionellosis is a well-known cause of pneumonia. Primary cutaneous and subcutaneous infection caused by Legionella pneumophila is rare and the diagnosis is challenging.
A 38-year-old Thai woman with systemic lupus erythematosus and myasthenia gravis treated with prednisolone and azathioprine presented to our hospital with low-grade fever, diarrhea, and indurated skin lesions on both thighs. Initial examination showed plaques on both inner thighs. Magnetic resonance imaging showed myositis and swelling of the skin and subcutaneous tissue. Diagnosis of panniculitis due to L. pneumophila was carried out by histopathology, Gram stain, and 16S rRNA gene sequencing method of tissue biopsy from multiple sites on both thighs. Myocarditis was diagnosed by echocardiography. The final diagnosis was disseminated extrapulmonary legionellosis. Treatment comprised intravenous azithromycin for 3 weeks and the skin lesions, myositis and myocarditis resolved. Oral azithromycin and ciprofloxacin were continued for 3 months to ensure eradication of the organism. The patient's overall condition improved.
To our knowledge, we report the first case of L. pneumophila infection manifesting with panniculitis, possible myositis, and myocarditis in the absence of pneumonia. The diagnosis of extrapulmonary Legionella infection is difficult, especially in the absence of pneumonia. A high index of suspicion and appropriate culture with special media or molecular testing are required. Initiation of appropriate treatment is critical because delaying therapy was associated with progressive infection in our patient.
军团病是一种众所周知的肺炎病因。由嗜肺军团菌引起的原发性皮肤和皮下组织感染较为罕见，诊断具有挑战性。
一名 38 岁的泰国女性，患有系统性红斑狼疮和重症肌无力，接受泼尼松龙和硫唑嘌呤治疗，因低热、腹泻和大腿双侧硬结性皮损到我院就诊。初步检查显示双侧大腿内有斑块。磁共振成像显示肌炎和皮肤及皮下组织肿胀。通过组织活检的组织病理学、革兰氏染色和 16S rRNA 基因测序方法，诊断为嗜肺军团菌引起的脂膜炎。通过超声心动图诊断为心肌炎。最终诊断为播散性肺外军团病。治疗包括静脉注射阿奇霉素 3 周，皮肤病变、肌炎和心肌炎得到缓解。继续口服阿奇霉素和环丙沙星 3 个月以确保消除病原体。患者整体状况得到改善。
据我们所知，我们报告了首例嗜肺军团菌感染表现为脂膜炎、可能的肌炎和心肌炎而无肺炎的病例。肺外军团菌感染的诊断较为困难，尤其是无肺炎时。需要高度怀疑并使用特殊培养基或分子检测进行适当培养。及时开始适当的治疗至关重要，因为在我们的患者中，延迟治疗与进行性感染有关。
