Abstract:

Chen Hao, Fu Meihua, Xu Changchun, Gao Wei, Zhang Xiaofeng, Sun Jianfang, Wang Hongsheng. Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China Corresponding authors: Fu Meihua, Email: meihuafu1974@aliyun.com; Wang Hongsheng, Email: whs33@vip.sina.com 【Abstract】 Objective To improve the understanding of cutaneous Mycobacterium haemophilum infection. Methods Clinical and laboratory data were collected from two patients with cutaneous Mycobacterium haemophilum infection. The clinical and histopathologic manifestations, etiology and treatment of cutaneous Mycobacterium haemophilum infection were analyzed. Results The two patients were both immunocompromised. Lesions, which occurred after trauma in both the patients, began as well-marginated subcutaneous nodules, and then gradually progressed into ulceration with crusting and abscess formation. Histopathological examination revealed epithelial cell granuloma or histiocytic infiltrate in the dermis, as well as focal necrosis and neutrophil abscesses. Acid-fast staining showed abundant bacilli in tissues. These bacilli only grew in iron-containing medium, and were finally identified as Mycobacterium haemophilum by PCR and sequencing. According to the result of antimicrobial sensitivity testing, both the patients were treated with rifampicin, clarithromycin and moxifloxacin. Three months later, the condition was improved in both of them. Conclusions Mycobacterium haemophilum infection occurs most frequently in immunocompromised populations after trauma, manifests as subcutaneous nodules and abscesses with histopathological changes consistent with infectious granuloma. Molecular biological approaches are reliable for the identification of Mycobacterium haemophilum.