Successful application of photodynamic therapy for skin infection caused by Corynespora cassiicola in an immunosuppressed patient and literature review

Corynespora cassiicola (C. cassiicola) is a common plant pathogen but occasionally causes infections in human skin. Poor outcome and death in such cases were then often reported even after a long course of antifungal treatment. In the present case, the patient was a 54-year-old farmer who presented with a ten-month history of an ulcerative lesion in the right lower extremity after a minor skin trauma. The patient had been undergoing immunosuppressive treatment for nephrotic syndrome for 2 months before the onset of the skin lesion. The fungal isolate from the lesion was identified as C. cassiicola by morphology and molecular sequencing. The patient was treated with ALA-PDT 5 times at 10 days intervals. The lesion disappeared and has not recurred in the 8-month follow-up. To our knowledge, it is the first time ALA-PDT has been used for treatment of a skin lesion caused by C. cassiicola. A retrospective analysis of the literature found 9 cases of C. cassiicola infection. All 9 patients had a history of immunodeficient conditions and had experienced a long course of antifungal therapy. Despite the rigorous antifungal treatment, 2 patients with CARD9 gene deficiency ultimately died. Our case suggests that photodynamic therapy is a potentially beneficial approach for treatment of fungal infection in immunosuppressed patients who failed to respond to antifungal agents.