Novel treatment using topical malachite green for nasal phaeohyphomycosis caused by a new Cladophialophora species in a cat

Abstract

Case summaryA 1.5-year-old castrated male domestic shorthair cat presented with a 2 month history of progressive nasal swelling and hyporexia. Minimal improvement prior to referral was achieved with a course of antibiotics and glucocorticoids. Cytology of an ulcerative lesion on the dorsal aspect of the nose was consistent with a diagnosis of phaeohyphomycosis. The cat achieved static disease for 6 weeks following initiation of itraconazole but developed epistaxis at 9 weeks. CT of the head demonstrated nasal and frontal sinus involvement. Nasal biopsy and culture identified infection with a Cladophialophora species not previously reported to cause disease. Initial response to a combination of itraconazole and terbinafine was noted, but owing to severe thrombocytopenia this combination was discontinued. Voriconazole was used but discontinued because of adverse side effects. Posaconazole treatment was offered throughout the clinical course but rejected owing to financial constraints and an uncertain response to medical therapy. Rhinotomy with debulking of diseased tissue and topical malachite green treatment was performed. Following the procedure itraconazole was continued and the cat has had no recurrence for over 1 year.Relevance and novel informationInfections by Cladophialophora species have been reported in veterinary species, including cats. The specific fungal organism isolated from this cat has not been previously reported to cause disease in humans or animals and has only been described in the mangroves of Brazil. Furthermore, this is the first report to describe the use of topical malachite green as a treatment for refractory phaeohyphomycosis.

First report of phaeohyphomycosis caused by Phialophora americana in a domestic cat from Argentina

“…In cases where an aggressive surgical excision cannot be performed, debulking is an essential option in association with the use of systemic antifungals. 3,21 In the present case, a second surgery with the aim of debulking the main nasal lesion could not be performed in the middle of the therapy, which complicated the response to antifungal treatment. The use of a combination of itraconazole and terbinafine has recently been reported for the treatment of a cat with phaeohyphomycosis caused by Cladophialophora species.…”

“… 20 The treatment of choice in phaeohyphomycosis includes surgical excision of the local lesions and the use of antifungal agents. 2 , 3 Reducing immunosuppressive treatment where possible is also important in treating these types of cases. In the present case, antifungal treatment and partial surgery of the nasal lesion were opted for because complete excision was a difficult procedure to perform in the compromised anatomic area and the owners declined invasive surgery.…”

“…The use of a combination of itraconazole and terbinafine has recently been reported for the treatment of a cat with phaeohyphomycosis caused by Cladophialophora species. 3 Although the clinical response was highly variable, good results were obtained for as long as it could be applied appropriately. The use of itraconazole in oral solution was useful because it allowed administration of a lower dose due to the high bioavailability that this formulation presents in cats.…”

“…several months and even combined with surgical procedures. [1][2][3] Some patients may have recurrences once the treatment has been completed. 4 The purpose of this case report is to describe, for the first time, Phialophora americana as a causal agent of phaeohyphomycosis in a cat from Argentina.…”

“…Antifungal therapy must be administered for several months and even combined with surgical procedures. 1 – 3 Some patients may have recurrences once the treatment has been completed. 4 …”