Mycetoma is a chronic, localized, slowly progressive, granulomatous infection of the skin that may progress to subcutaneous tissue, muscle and bone. It is an infrequent manifestation of Nocardia infection that predominantly occurs on the lower extremities.

A previously healthy, 17-year-old boy presented with a 3-month history of scalp abscesses. On physical examination he had numerous, large left parietal and occipital inflammatory nodules on the scalp covered by alopecic skin and several sinuses discharging a purulent and serosanguinous material. He underwent a CT-scan and an MRI of the skull that revealed signs of cranial osteomyelitis and epidural empyema. Polymerase chain reaction assay of the purulent exudate was performed and identified Nocardia nova. The patient was discharged from the hospital after 8 weeks of antibiotherapy with meropenem and TMP-SMX with clinical, laboratorial and imaging improvement. He completed 12 months of outpatient oral therapy with TMP-SMX, after which cranial CT-scan showed a significant reduction of soft tissue thickening and bone reconstitution, with no relapses after stopping the treatment.

The best antibiotic regimen and length of treatment are not established for the management of nocardiosis. This is an unusual and severe presentation of infection by Nocardia nova with extent to the bone and epidural space, with full recovery under standard antibiotic therapy. This case shows that a good outcome may be achieved with prolonged antimicrobial treatment in an immunocompetent patient.

足菌肿是一种慢性、局部、缓慢进展的皮肤肉芽肿感染，可进展到皮下组织、肌肉和骨骼。这是诺卡氏菌感染的一种罕见表现，主要发生在下肢。

一名既往健康的 17 岁男孩因头皮脓肿病史 3 个月就诊。体格检查时，他的头皮上有许多大的左顶叶和枕叶炎性结节，被脱发皮肤覆盖，几个鼻窦排出脓性和浆液性物质。他接受了颅骨 CT 扫描和 MRI，发现颅骨骨髓炎和硬膜外积脓的迹象。对化脓性渗出液进行聚合酶链反应测定并鉴定新诺卡氏菌. 患者在接受美罗培南和 TMP-SMX 8 周抗生素治疗后，临床、实验室和影像学均有所改善，出院。他用 TMP-SMX 完成了 12 个月的门诊口服治疗，之后头颅 CT 扫描显示软组织增厚和骨重建显着减少，停止治疗后没有复发。

诺卡菌病的最佳抗生素治疗方案和疗程尚未确定。这是新诺卡氏菌感染的一种不寻常且严重的表现，其范围扩展到骨骼和硬膜外腔，在标准抗生素治疗下完全恢复。该病例表明，对免疫功能正常的患者进行长期抗菌治疗可能会取得良好的结果。