Scedosporium apiospermum infection imitating lymphocutaneous sporotrichosis in a patient with myeloblastic-monocytic leukaemia

Recurrent Scedosporium apiospermum mycetoma successfully treated by surgical excision and terbinafine treatment: a case report and review of the literature

Background

Scedosporium apiospermum is an emerging opportunistic filamentous fungus, which is notorious for its high levels of antifungal-resistance. It is able to cause localized cutaneous or subcutaneous infections in both immunocompromised and immunocompetent persons, pulmonary infections in patients with predisposing pulmonary diseases and invasive mycoses in immunocompromised patients. Subcutaneous infections caused by this fungus frequently show chronic mycetomatous manifestation.

Case report

We report the case of a 70-year-old immunocompromised man, who developed a fungal mycetomatous infection on his right leg. There was no history of trauma; the aetiological agent was identified by microscopic examination and ITS sequencing. This is the second reported case of S. apiospermum subcutaneous infections in Hungary, which was successfully treated by surgical excision and terbinafine treatment. After 7 months, the patient remained asymptomatic. Considering the antifungal susceptibility and increasing incidence of the fungus, Scedosporium related subcutaneous infections reported in the past quarter of century in European countries were also reviewed.

Conclusions

Corticosteroid treatment represents a serious risk factor of S. apiospermum infections, especially if the patient get in touch with manure-enriched or polluted soil or water. Such infections have emerged several times in European countries in the past decades. The presented data suggest that besides the commonly applied voriconazole, terbinafine may be an alternative for the therapy of mycetomatous Scedosporium infections.

ScedosporiumSpecies Infections and Treatments

Scedosporium species are now increasingly isolated from immunocompromised and immunocompetent patients. Unfortunately, Scedosporium species infections are generally resistant to amphotericin B, and S. prolificans strains are particularly resistant to presently-available antifungal agents. Here we review the microbiology, expanding epidemiology, numerous clinical presentations, and diagnostic tools available for Scedosporium species infections. Finally, we detail the available in vitro, animal model, and clinical data on the treatment of Scedosporium species infections with special emphasis on the role of newer antifungal therapies for these recalcitrant infections.

Infections caused by Scedosporium spp

Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.

[Case of cutaneous Pseudallescheria boydii infection caused by trauma]

Pseudallescheria boydii is a ubiquitous filamentous fungus. We report a case of cutaneous P. boydii infection of the left knee in a 79-year-old Japanese man who was receiving oral predonisolone (25 mg/day) for radiation pneumonitis after radiation therapy on left breast cancer. He presented with a 2-week-history of a lesion on the left knee. A biopsy specimen from the skin lesion revealed granulomatous inflammation with hyphae. Culture of the pus from the skin specimen confirmed the diagnosis of cutaneous P. boydii infection. rDNA ITS sequence was analyzed to confirm the mycological diagnosis. The patient was treated orally with 200 mg/day of itraconazole. The lesion was gradually cured and left a hypertrophic scar. Cutaneous injury may be responsible for an incidence of localized infection. Such rare fungus infection in immunocompromised patients who have a persistent traumatic skin ulcer needs to be ruled out. An opportunistic infection in immunocompromised patients can be life-threatening and prompt treatment based on accurate diagnosis is important.

Scedosporium apiospermum: changing clinical spectrum of a therapy-refractory opportunist*

Current knowledge on the opportunist Scedosporium apiospermum (teleomorph: Pseudallescheria boydii), generated over a period of more than 120 years, is reviewed. The natural environmental habitat of the fungus is unknown; nutrient-rich, brackish waters like river estuaria have been suggested. The fungus is strongly promoted by agricultural and particularly by industrial pollution.

Scedosporium apiospermum soft tissue infection successfully treated with voriconazole: potential pitfalls in the transition from intravenous to oral therapy

An immunocompromised patient with an invasive soft tissue infection due to Scedosporium apiospermum was successfully treated with voriconazole and surgical debridement. After transition from intravenous to oral therapy, successive adjustments of the oral dose were required to achieve complete resolution. For soft tissue infections due to molds characterized by thin, septate hyphae branching at acute angles, voriconazole should be considered a first-line antifungal agent. The potential usefulness of plasma voriconazole levels for guiding optimal therapy should be investigated.

Recurrence of Scedosporium apiospermum infection following renal re-transplantation

Immunosuppression for organ transplantation results in increased susceptibility to opportunistic infections including fungal, such as Scedosporium apiospermum. Even though many reported cases of this infection had both local and systemic manifestations, majority of the systemic infections had a fatal outcome. We report a case of a 50-year-old Caucasian male with lymphocutaneous and presumed pulmonary Scedosporium infection 4 years after renal transplantation that was successfully treated with voriconazole and discontinuation of immunosuppression. He received a second transplant 3 years later in the absence of clinical evidence of S. apiospermum infection. Unfortunately, 4 months after transplantation he developed recurrence of the same infection localizing to the soft tissues. Presently this infection is under control with surgical excision and voriconazole therapy. To our knowledge this is the first reported case of recurrent S. apiospermum infection in a renal transplant recipient. We suggest prophylactic antifungal therapy in all re-transplants with this infection.

Invasive infections caused by Blastoschizomyces capitatus and Scedosporium spp

Blastoschizomyces capitatus, Scedosporium prolificans and S. apiospermum are emerging fungal pathogens that may cause disseminated disease in neutropenic patients. They can present as fever resistant to antibiotics and to wide-spectrum antifungal agents, although they may involve almost every organ. The proportion of recovery from blood cultures is high and they are characteristically resistant to most antifungal agents. Prognosis is poor unless patients recover from neutropenia. Voriconazole has good in-vitro activity and is currently the drug of choice for these infections.

Cutaneous infection due to Scedosporium apiospermum in an immunosuppressed patient

Scedosporium apiospermum, the anamorphic form of Pseudallescheria boydii, is a filamentous fungus with low inherent virulence. Increasing numbers of cases of this infection have been reported probably related to the rising number of immunosuppressed persons. Apart from mycetoma, cutaneous and subcutaneous infection is rarely encountered in clinical practice. We describe a case of cutaneous infection caused by Scedosporium apiospermum in a subject with rheumatoid arthritis and diabetes mellitus who was submitted to long-term therapy with cyclosporin and corticosteroids. Histopathologic examination of a skin biopsy showed a granulomatous infiltrate with hyaline septate hyphae. Culture of two skin biopsies taken at two different observations of the woman, 3 weeks apart, allowed isolation of Scedosporium apiospermum. Therapy with itraconazole, 400 mg/day, for 3 months was effective in curing the infection.

Case Reports. Infection due to Scedosporium apiospermum in renal transplant recipients: a report of two cases and literature review of central nervous system and cutaneous infections by Pseudallescheria boydii/Sc. apiospermum

Two cases of infections due to Scedosporium apiospermum in renal transplant recipients, one localized in the central nervous system, the other in the skin, are presented, and a literature review of 21 cases of central nervous system and cutaneous infections due to Pseudallescheria boydii/Sc. apiospermum is given.

Pseudallescheriasis as an aggressive opportunistic infection in a bone marrow transplant recipient

Pseudallescheria boydii is a low-virulence fungus that is the main causative agent of posttraumatic mycetoma in a nonimmunocompromised host. Immunocompromised patients are at high risk for locally invasive or disseminated Pseudallescheria infection. However, aggressive opportunistic infections due to P boydii are reported infrequently because it morphologically resembles other fungi, especially Aspergillus species, on tissue histology; therefore, such infections are not identified and treated properly. We report a case of disseminated P boydii infection in a patient following bone marrow transplantation. The identity of the fungus was not recognized until microbiologic culture results became available. Our case illustrates the importance of recognizing this fungus as an opportunistic infection in immunocompromised patients, as well as the need for culture of biopsy material for proper identification so that appropriate therapy can be instituted.

Successful outcome of Scedosporium apiospermum disseminated infection treated with voriconazole in a patient receiving corticosteroid therapy

A disseminated Scedosporium apiospermum infection was diagnosed in a woman with severe asthma and treated with corticosteroids. This fungi is resistant to fluconazole and amphotericin B. The infection was refractory to itraconazole, but responded successfully to voriconazole. A review of the literature is provided.

Cutaneous Scedosporium apiospermum infection in an immunocompromised patient

Scedosporium apiospermum infection occurred in the left forearm of a patient who was taking oral prednisolone for pulmonary fibrosis. The infection appeared to follow a scratch from a blackcurrant bush. This is the first reported case in the United Kingdom of a cutaneous infection from Scedosporium apiospermum in an immunocompromised patient.

Pathology of hyalohyphomycosis caused by Scedosporium apiospermum (Pseudallescheria boydii): an emerging mycosis

The genus Scedosporium contains two medically significant species of emerging mycotic agents, S. apiospermum and S. prolificans, which have received scant attention. Scedosporium apiospermum is the anamorph, or asexual state, of the cosmopolitan fungus Pseudallescheria boydii, with both sharing the same risk factors for infection, clinical spectrum, and histopathologic features. Scedosporium prolificans is a recently recognized agent of bone, soft tissue, and joint infections that occurs with highest frequency in children and young adults. S. prolificans may also cause potentially fatal disseminated infections in immunocompromised persons. The drug sensitivities of both Scedosporium species are significantly different from those of most other fungi, and thus identification of these organisms is important. Unfortunately, the pathological features of Scedosporium infections may be easily confused with other mycotic agents, resulting in delayed or inappropriate medical therapy. Because many pathologists and clinicians are unfamiliar with the significance of Scedosporium spp. infection, this communication describes three persons with differing clinical and pathological presentations of S. apiospermum infection. In one patient with sickle cell disease and chronic mycotic sinusitis, fungal colonies of S. apiospermum removed from the sinuses showed a pattern of alternating zones of mycelial hypercellularity and hypocellularity associated with conidiation, similar to a previous report of P. boydii infection. The clinicopathologic features of an immunocompetent person with S. apiospermum osteomyelitis, and a patient with S. apiospermum infection of the brain after bone marrow transplantation, are also described.

Scedosporium apiospermum sinusitis after bone marrow transplantation: report of a case

A forty-year-old man underwent an allogeneic BMT from his HLA identical sister. GvHD prophylaxis was done with cyclosporine (CyA), methotrexate and prednisone (PDN). On day +90 extensive GvHD was noted and higher doses of immunosuppressive drugs alternating CyA with PDN were initiated. Patient's follow-up was complicated by intermittent episodes of leukopenia and monthly episodes of sinusitis or pneumonia. One year after BMT, the patient developed hoarseness and nasal voice. No etiologic agent could be identified on a biopsy sample of the vocal chord. Upon tapering the doses of immunosuppressive drugs, the patient had worsening of chronic GvHD and was reintroduced on high doses of cyclosporine alternating with prednisone on day +550. Three months later, GvHD remained out of control and the patient was started on azathioprine. On day +700, hoarseness and nasal voice recurred. Another biopsy of the left vocal chord failed to demonstrate infection. Episodes of sinusitis became more frequent and azathioprine was withheld 3 months after it was started. One month later, the patient had bloody nasal discharge and surgical drainage of maxillary sinuses was performed. Histopathology showed hyphae and cultures grew Scedosporium apiospermum. Itraconazole 800 mg/day was initiated. The patient developed progressive respiratory failure and died 15 days later.