Clinical presentation of zygomycosis

Abstract

Zygomycetes are filamentous fungi with a worldwide distribution. This class of fungi encompasses two orders, i.e. the Mucorales and the Entomophthorales. Members of the latter are associated with chronic cutaneous and subcutaneous infections that are limited to the tropics and rarely disseminate to internal organs. The order Mucorales includes several species involved in rhinocerebral, pulmonary, cutaneous, gastrointestinal and other less frequent infections in immunocompetent and immunocompromised individuals, and is characterized by a tendency to disseminate. Portals of entry of zygomycetes are usually the lungs, skin, and gastrointestinal tract. A characteristic property of zygomycetes is their tendency to invade blood vessels and to cause thrombosis-processes that result in subsequent necrosis of involved tissues. Risk factors associated with zygomycosis include prolonged neutropenia and use of corticosteroids, solid organ or haematopoietic stem cell transplantation, AIDS, poorly controlled diabetes mellitus, iron chelation with deferoxamine, burns, wounds, malnutrition, extremes of age, and intravenous drug abuse. Recently, the widespread use of voriconazole for prophylaxis or treatment of aspergillosis in patients with haematological malignancies has been linked with a rise in the numbers of cases of invasive zygomycosis. As the symptoms, clinical signs and imaging findings of these infections are non-specific, a high index of suspicion is required for timely diagnosis. Early diagnosis, correction of the underlying predisposing factors, aggressive surgical debridement of all infected tissues and lengthy administration of antifungals are the only potentially curative options for this rare but emerging invasive fungal infection.

Evaluation of patients with zygomycosis

“…Rhinocerebral zygomycosis is characterized by nasal and paranasal sinus involvement as well as orbital, cavernous sinus, and cerebral involvement (9). In our study, the rhinocerebral form (including the rhino-orbital form) was identified in 10 patients, 7 of whom died.…”

“…Diagnosis of zygomycosis was made in accordance with the criteria issued by European Organization for Research and Treatment of Cancer/Mycoses Study Group (13). The clinical forms of zygomycosis have been defined based on the involved organ: rhinocerebral (rhino-orbito-cerebral, rhino-orbital), cutaneous, pulmonary, gastrointestinal, and disseminated (3,9). As well as the clinical findings, radiological imaging methods (computed tomography and magnetic resonance imaging) and endoscopic methods (rhinoscopy, gastrointestinal endoscopy) were used to detect the localization of the infections.…”

“…Nasal congestion, headache, maxillary pain, hyposmia, and anosmia may be seen. In addition, the presence of necrotic scarring in the nasal cavity and necrotic facial lesions indicate an angioinvasive infection (8)(9)(10)(11)(12).…”

Human Mucormycosis

“…The common risk groups include those on therapeutic interventions corticosteroid therapy, solid tumors and solid organ transplant recipients, acquired or congenital neutropenic patients, those with hematologic disorders and hematopoietic stem cell transplant recipients. In last decades, a link has been reported between infection with the Rhizopus species and resistant gram-negative bacteria which can produce endosymbiotic toxin [4,5]. Hemodialysis patients under treatment with deferoxamine, due to high concentration of free iron in plasma and tissues are at risk for mucormycosis [6].…”

“…The presentation type of this infection usually depends on the underlying host conditions [4]. Hyperglycemia and low pH in diabetic patients are the most important risk factors.…”