P051 A case of recalcitrant sporotrichosis by infection of Sporothrix globosa

Abstract

Abstract Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM Objectives Sporotrichosis is the leading subcutaneous mycosis caused by the Sporothrix (S.) schenckii complex. S. globosa is the causative organism of fixed sporotrichosis in Korea. The preferred regimen of cutaneous sporotrichosis is itraconazole for 3-6 months, however, there were few studies for recalcitrant sporotrichosis. Methods In 2018, we performed a histological examination of a patient who suffered sporotrichosis for 3 years and cultured part of the specimen. Despite various regimens for years, improvement and exacerbation were repeated, so we took another skin biopsy and cultured it in 2021. Isolates from the 2018 and 2021 lesions were identified as S. globosa by ribosomal DNA ITS sequencing (GenBank accession number: MH499862 and MH499863). The in vitro antifungal sensitivity tests were performed by broth microdilution method according to CLSI M38-A2 guidelines or Sensititre YeastOne® manufacturer's instructions. They were incubated at 30°C in a non-CO2 incubator for 7 days. Results In 2018, histologically, we observed chronic inflammatory granuloma comprising lymphocytes, histiocytes, and giant cells, and several spores with periodic acid-Schiff (PAS) staining. Microscopic findings and ITS sequences of rRNA gene were identical with S. globosa. The antifungal susceptibility profile in 2018 revealed sensitive to terbinafine (0.125 μg/ml), and moderate to high MIC values for amphotericin B (2 μg/ml), itraconazole (>16 μg/ml), voriconazole (>16 μg/ml), and echinocandins (>16 μg/ml). Treatment with terbinafine, itraconazole, or amphotericin B, the skin lesions were partially improved, but were not cured. In 2021, we took another skin biopsy and culture specimen. Histopathological and mycological examination results were the same as before. The antifungal susceptibility profile revealed sensitive to itraconazole (0.5/ml), and high MIC for others. Clinically, skin lesions were not improved with the use of itraconazole 200 mg/d. Itraconazole 400 mg/d with local heating induced moderate improvement. There was no evidence of immune deficiency. Conclusion We experienced recalcitrant sporotrichosis that did not respond to itraconazole and terbinafine, and the sensitivity of antifungal was changed. In this case, the combination treatment including local heating, saturated KI may be considered, and frequent antifungal susceptibility tests are needed.