Intralesional amphotericin B in a cat with cutaneous protothecosis.

A domestic cat was presented with nodular lesions on the nose/muzzle and pinnae. Protothecosis was diagnosed through cytological and histopathological examination, and culture. Molecular identification confirmed Prototheca wickerhamii infection. Intralesional application of amphotericin B in conjunction with oral terbinafine resulted in a significant reduction of the nasal lesion and complete resolution of the pinnal lesion, without adverse effects.

Un chat domestique est présenté avec des lésions nodulaires sur le nez/museau et le pavillon auriculaire. La protothécose est diagnostiquée par un examen cytologique et histopathologique, ainsi que par une culture. L'identification moléculaire confirme l'infection par Prototheca wickerhamii. L'application intralésionnelle d'amphotéricine B, associée à la terbinafine orale, permet une réduction significative de la lésion nasale et une résolution complète de la lésion du pavillon auriculaire, sans effets indésirables.

Um gato doméstico foi apresentado com lesões nodulares no nariz/focinho e pavilhões auriculares. Prototecose foi diagnosticada por exame citológico e histopatológico, e cultura. A identificação molecular confirmou a infecção por Prototheca wickerhamii. Aplicação intralesional de anfotericina B associada à terbinafina por via oral resultou em redução significativa da lesão nasal e resolução total da lesão na orelha, sem efeitos adversos.

Un gato doméstico se presentó con lesiones nodulares en la nariz/hocico y orejas. Se diagnosticó prototecosis mediante examen citológico, histopatológico y cultivo. La identificación molecular confirmó la infección por Prototheca wickerhamii. La aplicación intralesional de anfotericina B junto con terbinafina oral dio como resultado una reducción significativa de la lesión nasal y una resolución completa de la lesión auricular, sin efectos adversos.

Cutaneous protothecosis in a dog successfully treated with oral itraconazole in pulse dosing.

BACKGROUND: Protothecosis is a rare infectious disease caused by unicellular, achlorophyllous, microalgae of the genus Prototheca, ubiquitously distributed in nature. The algae are emerging pathogens, whose incidence is increasing in both human and animal populations and serious systemic infections related to this pathogen have been increasingly described in humans in recent years. After mastitis in dairy cows, canine protothecosis is the second most prevalent form of the protothecal disease in animals. Here, we report the first case of chronic cutaneous protothecosis due to P. wickerhamii in a dog in Brazil, successfully treated with a long-term therapy with itraconazole in pulse. CASE PRESENTATION: Upon clinical examination, exudative nasolabial plaque, ulcered, and painful lesions in central and digital pads and lymphadenitis were observed in a 2-year-old mixed-breed dog, with a 4-month history of cutaneous lesions and contact with sewage water. Histopathological examination revealed intense inflammatory reaction, with numerous spherical to oval, encapsulated structures stained with Periodic Acid Schiff, compatible with Prototheca morphology. Tissue culture on Sabouraud agar revealed yeast-like, greyish-white colonies after 48 h of incubation. The isolate was subjected to mass spectrometry profiling and PCR-sequencing of the mitochondrial cytochrome b (CYTB) gene marker, leading to identification of the pathogen as P. wickerhamii. The dog was initially treated with oral itraconazole at a dosage of 10 mg/kg once daily. After six months, the lesions resolved completely, yet recurred shortly after cessation of therapy. The dog was then treated with terbinafine at a dose of 30 mg/kg, once daily for 3 months, with no success. The resolution of clinical signs, with no recurrence over a 36-months follow-up period, was achieved after 3 months of treatment with itraconazole (20 mg/kg) in pulse intermittently on two consecutive days a week. CONCLUSIONS: This report highlights the refractoriness of skin infections by Prototheca wickerhamii with therapies proposed in the literature and suggests a new treatment option with oral itraconazole in pulse dosing for long-term disease control successfully performed in a dog with skin lesions.