First case of pulmonary sporotrichosis caused by Sporothrix schenckii complex reported in Argentina
January 30 2018
Sporotrichosis is a rare infection that usually occurs after the skin is pierced by plant material carrying the dimorphic fungus Sporothrix. A pulmonary form is occasionally seen in patients who have inhaled conidia, but only around 100 cases of this have ever been reported, so accurate incidence and prevalence rates are not available. Radiology can distinguish between unifocal pulmonary infections and multifocal (disseminated) infection, as unifocal infections commonly display cavitary patterns while the latter more often appear as bibasal or diffuse infiltrates.
Dr Florencia Rojas and colleagues have published a case report and literature review that sheds light on primary pulmonary sporotrichosis. They describe a case in Argentina where a 65-year-old housewife presented with septic shock and multiorgan failure from a respiratory focus. Klebsiella pneumoniae and Staphylococcus aureus were isolated but she did not respond to antibiotic treatment in the first two weeks. A CT scan revealed cavitated consolidation in the right upper lobe with pleural effusion, while a BAL sample sent off to a university mycology lab was found to contain Sporothrix schenckii complex (the first such case in Argentina). The patient was treated with liposomal amphotericin B, then switched to long-term daily itraconazole following her discharge from hospital at 60 days.
In this case the patient’s long history of smoking may have been a predisposing factor, but other risk factors to watch out for include chronic alcoholism (seen in 40% of cases) and occupational/environmental exposure especially among gardeners and forestry workers (seen in 50% of cases). Sporothrix yeast cells are tricky to detect by direct microscopy, so performing cultures from lung exudates is advised. Treatment is difficult, and current guidelines (compiled by IDSA and later endorsed by ATS) are by necessity based on low-level evidence from case reports.
CT showing single cavity in right lung, bilateral symmetrical pleural effusion, infiltration in right basal alveolar interstitial area with ground glass in the upper left lobe(image from Rojas et al 2017).