Cutaneous Alternaria infectoria infection in a dog in association with therapeutic immunosuppression for the management of immune‐mediated haemolytic anaemia

Abstract

A 4-year-old, ovariohysterectomized, English springer spaniel on immunosuppressive therapy was re-examined for the review of its immune-mediated haemolytic anaemia and the recent development of skin lesions. For the 3 months since hospital discharge, the dog had been receiving 1.3 mg/kg prednisolone and 2.6 mg/kg ciclosporin, both administered orally twice daily. Physical examination revealed hepatomegaly and multiple, purulent, crusting, erosive to ulcerative lesions over different body areas. Onychorrhexis had occurred on one digit and the underlying corium had blackened. There were two proliferative and one plaque-like lesions in the mouth. Thick walled fungal hyphae were detected in impression smears from all skin lesions and staining with periodic acid-Schiff's stain confirmed the presence of multiple fungal hyphae and spores in all biopsies examined. Fungal culture isolated a heavy, pure growth of an Alternaria sp. which was identified as A. infectoria by sequencing the internal transcribed spacer 1 region of the rRNA gene. The animal's condition prevented detailed investigation of the oral lesions. Withdrawal of the ciclosporin and reduction of the prednisolone dosage resulted in spontaneous resolution of the skin lesions within 40 days. Further gradual decrements in the prednisolone dosage to zero were carried out without recurrence of the immune-mediated haemolytic anaemia. After 12 months, there has been no recurrence of either the skin lesions or the anaemia. To the authors' knowledge, this is the first reported case of A. infectoria infection in a dog.

Phaeohyphomycoses, Emerging Opportunistic Diseases in Animals

“…In another study by Dedola et al, Alternaria infectoria was isolated from multiple, purulent, crusting, and erosive to ulcerative lesions over different body areas in a dog under therapeutic immunosuppression (87). Onychorrhexis had occurred on digits, and the underlying corium had blackened (Fig.…”

“…Reports of deep infections in cats include nasal (80), renal (81), and ocular (82) involvement, as well as cerebellar infection (83). Cutaneous, subcutaneous, and systemic phaeohyphomycoses due to Cladophialophora bantiana, Phialophora verrucosa, Fonsecaea pedrosoi, Exophiala spinifera, Alternaria alternata, and A. infectoria have been documented in cats (79,(84)(85)(86)(87)(88)(89)(90)(91)(92).…”

Facial cutaneous phaeohyphomycosis associated with Alternaria infectoriae infection

“…A compromised immune system seems to play a major role in human disease and in the only documented case of A. infectoriae infection in a dog (Dedola et al . ). Despite the fact that steroid therapy and Cushing's syndrome are known risk factors in human patients, infection in cats and horses has not been associated yet with any underlying disease.…”

Opportunistic Invasive Cutaneous Fungal Infections Associated with Administration of Cyclosporine to Dogs with Immune‐mediated Disease

“…infection; however, this appears to be uncommon. Infections with nonpigmented filamentous ascomycetes (aspergillosis and hyalohyphomycoses) and pigmented fungi (phaeohyphomycosis) are typical OIFIs in dogs . These organisms are ubiquitous soil saprophytes.…”

“…There have been individual case reports and 1 case series of 8 dogs describing OIFIs in immunosuppressed dogs. The case series of 8 dogs with OIFIs that had received cyclosporine and prednisone treatment emphasized the severe and occasionally fatal consequences of these infections .…”