Disseminated fusariosis with ecthyma gangrenosum-like lesions in a refractory acute myeloid leukemia patient

The Medical Relevance of Fusarium spp

The most important medical relevance of Fusarium spp. is based on their phytopathogenic property, contributing to hunger and undernutrition in the world. A few Fusarium spp., such as F. oxysporum and F. solani, are opportunistic pathogens and can induce local infections, i.e., of nails, skin, eye, and nasal sinuses, as well as occasionally, severe, systemic infections, especially in immunocompromised patients. These clinical diseases are rather difficult to cure by antimycotics, whereby the azoles, such as voriconazole, and liposomal amphotericin B give relatively the best results. There are at least two sources of infection, namely the environment and the gut mycobiome of a patient. A marked impact on human health has the ability of some Fusarium spp. to produce several mycotoxins, for example, the highly active trichothecenes. These mycotoxins may act either as pathogenicity factors, which means that they damage the host and hamper its defense, or as virulence factors, enhancing the aggressiveness of the fungi. Acute intoxications are rare, but chronic exposition by food items is a definite health risk, although in an individual case, it remains difficult to describe the role of mycotoxins for inducing disease. Mycotoxins taken up either by food or produced in the gut may possibly induce an imbalance of the intestinal microbiome. A particular aspect is the utilization of F. venetatum to produce cholesterol-free, protein-rich food items.

An Overview of the Management of the Most Important Invasive Fungal Infections in Patients with Blood Malignancies

In patients with hematologic malignancies due to immune system disorders, especially persistent febrile neutropenia, invasive fungal infections (IFI) occur with high mortality. Aspergillosis, candidiasis, fusariosis, mucormycosis, cryptococcosis and trichosporonosis are the most important infections reported in patients with hematologic malignancies that undergo hematopoietic stem cell transplantation. These infections are caused by opportunistic fungal pathogens that do not cause severe issues in healthy individuals, but in patients with hematologic malignancies lead to disseminated infection with different clinical manifestations. Prophylaxis and creating a safe environment with proper filters and air pressure for patients to avoid contact with the pathogens in the surrounding environment can prevent IFI. Furthermore, due to the absence of specific symptoms in IFI, rapid and accurate diagnosis reduces the mortality rate of these infections and using molecular techniques along with standard mycological methods will improve the diagnosis of disseminated fungal infection in patients with hematologic disorders. Amphotericin B products, extended-spectrum azoles, and echinocandins are the essential drugs to control invasive fungal infections in patients with hematologic malignancies, and according to various conditions of patients, different results of treatment with these drugs have been reported in different studies. On the other hand, drug resistance in recent years has led to therapeutic failures and deaths in patients with blood malignancies, which indicates the need for antifungal susceptibility tests to use appropriate therapies. Life-threatening fungal infections have become more prevalent in patients with hematologic malignancies in recent years due to the emergence of new risk factors, new species, and increased drug resistance. Therefore, in this review, we discuss the different dimensions of the most critical invasive fungal infections in patients with hematologic malignancies and present a list of these infections with different clinical manifestations, treatment, and outcomes.

The skin and soft tissue infections in hematological patients

PURPOSE OF REVIEW

Skin and soft tissue infections (SSTIs) in patients with hematological malignancies are frequent, but dedicated epidemiological studies are limited. The aim of this review is to provide updated description of the main etiological agents, differential diagnosis, and treatment.

RECENT FINDINGS

In addition to common causes of bacterial skin infections in any kind of patients, such as streptococci and staphylococci (the letter frequently resistant to methicillin), Pseudomonas aeruginosa is a frequent agent in patients with hematological malignancies, with high virulence and typical infection presenting as ecthyma gangrenosum. Among fungi, fusariosis is the mold infection most frequently associated with skin lesions, although other molds and yeasts (including Candida tropicalis) should be also considered. External infections associated with central venous catheters are frequent in the hematological setting, and in addition to staphylococci, Gram-negative bacteria, fungi, and even rapid growing nontuberculous mycobacteria should be considered. Immunodeficiency might either blunt the typical inflammatory response and make sign or symptoms less evident, or predispose the patients to rapid progression of skin infection to subcutaneous tissues or dissemination.

SUMMARY

SSTIs in hematology patients can be caused by various infectious agents resulting in similar clinical presentation. Rapid and accurate diagnosis is fundamental in order to reduce morbidity and mortality.