Scedosporium apiospermum infections are rare. This fungi can present causing superficial skin and wound infections, or with invasive disease. Bone, sinus, prosthetic valve, eye, lung, brain, pericardium, kidney, and disseminated infections have been described. Pleural infection has been reported only in 2 cases. Invasive infections have a high mortality, and have been reported mainly in immunocompromissed hosts. The other groups of patients susceptible to invasive disease are trauma or near-drowning victims, and farmers. Sc. apiospermum is the asexual form of Pseudallescheria boydii. This microorganism has also been called Monosporium apiospermum, Petrellidium boydii, and Allescheria boydii.
A seventy-year-old male was admitted for investigation of left sided pleural thickening and effusion.One month before, the patient presented to one of our clinics complaining of dull pain on the left hemithorax for 2 months. Chest radiograph (CXR) and chest computed tomography (CT) revealed pleural thickening above the left costophrenic angle. In addition, a small amount of air was seen inside the thickened pleura on chest CT. The process was felt to represent an anaerobic infection, and amoxacillin/clavulanate was prescribed.Repeat CXR and chest CT done one month later showed progression of the pleural process with development of effusion. His clinical status was unchanged.Past medical history was significant for celiac disease and malnutrition. The patient was not taking any immunosuppressants.Physical examination was remarkable for: a chronically ill looking cachectic patient, poor dentition, decreased breath sounds on the left lower lung field, and 2 + ankle and pre-tibial edema. He was not neutropenic, and his albumin and pre-albumin were 1.3 g/dl and <7.4 mg/dl respectively.Thoracentesis revealed an exudative effusion with neutrophil predominance. Smears were negative for AFB/fungal/bacteria.Pleural fluid culture showed masses of septate hyphae, later identified as Sc. apiospermum.A second thoracentesis was performed and the culture again was positive for the fungi. Cardio-thoracic surgery was consulted, and the patient was deemed not to be a surgical candidate due to his poor performance and nutritional status.Treatment with voriconazole was started.Eight days later the patient became hypotensive and was transferred to the intensive care unit. Treatment for nosocomial pneumonia was instituted. On ICU day 4, patient developed left sided hemiparesis. Head CT demonstrated large hypodense areas in the right basal ganglia, right frontal, and right parietal lobes with presence of air in those areas. The patient continued to deteriorate and died on ICU day 6. No permission for autopsy was granted.DISCUSSION: We report the third case of pleural infection due to Sc. apiospermum. There is only one case of primary pleural infection reported previously; an immunocompetent patient treated with decortication with good results. The other reported case of pleural involvement, occurred in a lung transplant recipient that developed lung infection and pleural effusion secondary to the fungi with subsequent dissemination. We considered our patient to be immunosupressed due to his severe degree of malnutrition. His case was complicated by dissemination of the disease. The large ischemic changes and the presence of air in the brain parenchyma seen on head CT were most likely secondary to the fungi. Sc apisopermum is known to cause brain infarcts, abscesses, necrosis, and mycotic aneurysms.Surgical debridement/resection and voriconazole are recommended for the treatment of invasive infections. Other options include intraconazole, miconazole, and ketoconazole. The fungus is usually resistant to amphotericin B. Unfortunately our patient’s nutritional and performance status precluded surgical treatment.
Sc apiospermum should be considered in the differential diagnosis of pleural thickening and/or pleural effusion in immunosupressed patients. Its isolation from a sterile site represents infection. Accurate diagnosis is crucial to institute adequate treatment.
P.E. Molina, None.