A patient with infectious back pain. Clinical and Therapeutic issues.

Introduction: Back pain is a common symptom generally benign. However, serious conditions, such as endocarditis, infectious aortitis (IA) and spondylodiscitis (SD), could present with dorsal and lumbar pain. IA and SD are rare, clinically non-specific and require long term antibiotic therapy, although there is no consensus on antibiotic treatment duration. Case description: We present a case of an ex-smoker 73-year-old male with an history of hypertension, discal hernia L4-L5 and L5-S1, and two episodes of pulmonary embolism (PE)12 years before and a month before, respectively. The patient was admitted emergently with lumbar and dorsal pain, leg weakness, fever, and dyspnea. The previous month, he was treated with intra muscular analgesic injections because of severe back pain. A contrast enhanced chest computed tomography angiography (CTA) performed at admission revealed an aortic localized perforation of thoracic aorta and a contained leak in the surrounding tissue. Emergent surgery was performed and infectious aortitis was identified. Intra operative findings showed a severe atherosclerosis of the thoracic aorta, with several ulcerated plaques. Ascending aorta and aortic arch was removed and replaced with an in situ prosthetic graft. Left carotid and brachiocephalic arteries were re-implanted into the graft. Cultures of the surgical materials showed a Meticillin-sensitive Staphylococcus aureus (MSSA) infection. Antibiotherapy was empirically started with piperacillin/tazobactam and teicoplanine replaced by oxacillin once obtained culture’s results. Further imaging examinations showed a L4-L5 SD and involvement of pre and paravertebral muscles, left and right psoas muscles, and the epidural soft tissue. Moreover, two abscesses of left buttock and right buttock were observed. Percutaneous sonographically-guided drainage of both abscesses was performed, and cultures isolated MSSA. After 5 weeks of intra venous antibiotherapy, it was started an oral antibiotic therapy (ciprofloxacin and amoxicillin/clavulanate, then modified with rifampicin and trimethoprim/sulfamethoxazole) which targeted the pathogen and the site of infection (aorta, lumbar vertebrae and the interposed disk). The patient responded to antibiotherapy with rapid defervescence. During the monitoring, the patient complicated with pneumonia and uveitis treated with linezolid and steroids, respectively. Abscesses were probably caused by intramuscular injections and represented a focus of continuous bacteremia that led to aorta and vertebral infection. At the moment, after 17 weeks from surgery, the patient is asymptomatic, but still on antibiotherapy. Discussion: This case is of interest for several reasons. There is no case in literature of IA associated with SD and buttock abscesses. Moreover, guidelines on therapy are missing. Emergent surgery, long-term antibiotic treatment and close monitoring, collaboration among health care workers achieved a good outcome.