Skin infection and progressive paraparesis

Abstract

A 35-year-old female agricultural worker presented with a 4 month history of productive cough, fever, and left subcostal pain, followed by progressive paraparesis and urinary incontinence. 10 years previously, she had been treated for a skin infection on her back at another centre for 3 years, without further follow-up. Examination showed more than one irregular scars, hyperpigmented papules, and few skin sinuses with scanty purulent discharge, without erythema, on the middle and left side of the upper back. The patient was afebrile and did not have palpable cervical or supraclavicular lymphadenopathy. We heard no rales, rhonchi, or substantial wheezing. The patient had fl accid paraplegia with complete sensory loss at T4 level and urinary sphincter incontinence. Laboratory tests showed a leucocyte count of 9·1 cells per μL, a normal liver enzyme profi le, a C-reactive protein concentration of 59·1 mg/dL (normal range 0–0·5 mg/dL), and no evidence of venereal disease or HIV. Protein concentration in her cerebrospinal fl uid was 800 mg/dL, glucose was 32 mg/dL, and no cells were present. Cerebrospinal fl uid stains, bacterial culture, and PCR for Mycobacterium tuberculosis were negative. Chest radiography showed a paravertebral mass with a fragmentary pattern of osseous patchy destruction and periosteal reaction (fi gure, A). Spiral CT showed a left paravertebral extensive osteolytic lesion involving vertebral bodies and costovertebral unions (fi gure, B). T2-weighted MRI (fi gure, C–E) showed widespread hyperintense lesions that infi ltrated vertebral bodies without involvement of intersomatic spaces (arrow), pleural thickening, and lung consolidation of the left lower lobe (asterisks). Gram stain and modifi ed acid-fast stain (Kinyoun) of sinus discharge showed variably Gram-positive and faintly acid-fast positive, slender, non-branching fi lamentous bacilli, consistent with a diagnosis of Nocardia sp. Intravenous amikacin, co-trimoxazole, and an orthopaedic corset were indicated. Surgery for debridement was off ered, but the patient did not choose to have the procedure. The patient attended our neurological care centre 2 months after discharge and showed a discrete amelioration of neurological symptoms, but did not return for further follow-up. Initially, diff erential diagnosis included extramedullary neoplasms and granulomatous infections (aspergillosis, histoplasmosis, tuberculosis, chromomycosis, blastomycosis, coccidiodomycosis, botryomycosis, sporotrichosis, frambesia, and syphilis). Gadolinium MRI is especially useful because it could help the practitioner to diff erentiate between vertebral intraosseous abscesses, meningeal involvement, subligamentous spread, and paraspinal abscess.