Histopathological clues in the diagnosis of fungal infection byScedosporiumin a case of endophthalmitis starting as conjunctivitis

Scedosporiosis and lomentosporiosis: modern perspectives on these difficult-to-treat rare mold infections

SUMMARYAlthough Scedosporium species and Lomentospora prolificans are uncommon causes of invasive fungal diseases (IFDs), these infections are associated with high mortality and are costly to treat with a limited armamentarium of antifungal drugs. In light of recent advances, including in the area of new antifungals, the present review provides a timely and updated overview of these IFDs, with a focus on the taxonomy, clinical epidemiology, pathogenesis and host immune response, disease manifestations, diagnosis, antifungal susceptibility, and treatment. An expansion of hosts at risk for these difficult-to-treat infections has emerged over the last two decades given the increased use of, and broader population treated with, immunomodulatory and targeted molecular agents as well as wider adoption of antifungal prophylaxis. Clinical presentations differ not only between genera but also across the different Scedosporium species. L. prolificans is intrinsically resistant to most currently available antifungal agents, and the prognosis of immunocompromised patients with lomentosporiosis is poor. Development of, and improved access to, diagnostic modalities for early detection of these rare mold infections is paramount for timely targeted antifungal therapy and surgery if indicated. New antifungal agents (e.g., olorofim, fosmanogepix) with novel mechanisms of action and less cross-resistance to existing classes, availability of formulations for oral administration, and fewer drug-drug interactions are now in late-stage clinical trials, and soon, could extend options to treat scedosporiosis/lomentosporiosis. Much work remains to increase our understanding of these infections, especially in the pediatric setting. Knowledge gaps for future research are highlighted in the review.

A case of fungal conjunctivitis with giant papillae treated surgically

Fungal conjunctivitis is a rare disorder, with low incidence and difficulty in diagnosis due to a lack of specific clinical findings. We report a case of fungal conjunctivitis which exhibited a specific clinical feature of giant papilla formation, and its diagnosis was a complex process. A 19-year-old woman with a history of atopic dermatitis and hard contact lens use was referred to us with a 3-month history of giant papillary conjunctivitis of the right eye in spite of treatment with antiallergic and corticosteroid eye drops, complicated by intraocular pressure elevation. The left eye showed no symptom of ocular surface disorder throughout the clinical course. The right eye did not respond to oral corticosteroid. Polymerase chain reaction of conjunctival scrapings against Chlamydia trachomatis was negative, and she was treated surgically by total papilla resection. Conjunctival giant papilla recurrence was not observed after surgery. Although the primary histopathological diagnosis was chronic inflammation due to atopic keratoconjunctivitis, repeated histopathological survey of excised conjunctival tissue including immunohistochemical staining revealed histiocytes, yeast type spores and hyphae, and phagocytosed spores and hyphae in macrophages. The causative organism was identified morphologically as a Candida species. Later, histopathological examination of a cervical swab revealed the presence of Candida sp. This rare case indicates that a fungal organism may underlie refractory conjunctivitis with specific giant papillary hypertrophy mimicking vernal keratoconjunctivitis.

Pseudallescheria/Scedosporium complex species: From saprobic to pathogenic fungus

Scedosporiosis is an emerging fungal infection caused by Pseudallescheria/Scedosporium complex species (PSC). This pathogen has been drawn significant interest in recent years due to its worldwide prevalence, the seriousness of its infection, associated with high mortality in both immunocompromised and immunocompetent hosts and its cryptic ecology, distribution and epidemiology across the globe. These species complexes can be found in environments impacted by human. The purpose of this review is to describe the characteristics, mode of transmission, ecology, prevalence, global epidemiology of this fungal group in order to increase the awareness of among clinicians and microbiologists, especially in regions with high endemic, as well as to promote further research on all of its aspects.