Title : A rare encounter: Disseminated nocardiosis following myasthenia gravis treatment
Abstract:
Nocardiosis is an uncommon opportunistic infection caused by filamentous Gram-positive bacteria of the genus Nocardia, predominantly affecting immunocompromised hosts. Immunosuppressive therapy, such as Rituximab, significantly increases susceptibility to such infections . Myasthenia Gravis poses a unique challenge in such cases as the aminoglycosides and fluoroquinolones are restricted to prevent exacerbations .
Here we report the case of a 45-year-old male with myasthenia gravis, diagnosed 8 months prior, presenting with diminished vision in his right eye 20 days after receiving Rituximab. Initially diagnosed with endophthalmitis, he subsequently developed fever, productive cough, and pustular skin lesions on his chest and left forearm.A CT chest revealed cavitary consolidation in the left lingula with perifocal consolidation. Wound swabs grew filamentous Gram-positive bacteria, while blood cultures grew Nocardia spp later identified as Nocardia Farcinica. MRI brain revealed multiple fronto-temporo-occipital abscesses, consistent with CNS dissemination.
The patient was treated with intravenous Imipenem-Cilastatin, Cotrimoxazole, and Linezolid for six weeks. By the end of this regimen, there was marked improvement in respiratory symptoms and resolution of skin lesions. Repeat MRI brain showed significant reduction in abscess size. Due to resource constraints, antibiotic sensitivity testing was not performed. The patient was discharged on oral Cotrimoxazole, planned for a 12-month course with monthly follow-up.
This case highlights the critical need for vigilance in immunocompromised patients, particularly those on biologic therapies like Rituximab. Early diagnosis and prolonged combination antibiotic therapy are key to successful outcomes in disseminated nocardiosis
