Fungal Infections

Mucormycosis: Clinical Syndromes

1. RHINOCEREBRAL MUCORMYCOSIS Rhinocerebral mucormycosis occurs most commonly in patients with uncontrolled diabetes, especially after an episode of diabetic ketoacidosis. It may also occur in leukemic patients who have had prolonged neutropenia and therapy with broad-spectrum antibiotics and occasionally in organ transplant recipients. Clinical Findings A. Signs and Symptoms. The earliest symptoms in rhinocerebral mucormycosis are facial pain, headache, and nasal stuffiness. As the disease progresses, orbital pain and facial anesthesia may be noted. Double vision or loss of vision may develop after invasion of the orbit by the rapidly spreading infection. Mental status changes herald the penetration into the brain with ensuing cavernous sinus thrombosis, carotid artery thrombosis, and cerebral …

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Pseudallescheria Boydii Infection

Essentials of Diagnosis Filamentous fungus that is morphologically similar to Aspergillus spp. Most serious infections occur in immunosuppressed patients. Recovery from culture must be distinguished from colonization or contamination. General Considerations P boydii is a mold that is capable of causing infection in immunosuppressed patients and less frequently in immunocompetent patients. Overall, infection with P boydii is rare. A. Epidemiology. Although a relatively common environmental mold, P boydii is a rare cause of human disease. It can be easily recovered from soil, water, and manure. Both community and nosocomial acquisition have been documented. In most instances, its recovery from culture specimens will reflect colonization or contamination; however, it is capable of …

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Aspergillus Sinusitis

Aspergillus spp. are capable of causing a variety of infections involving the paranasal sinuses (Table 2). Although uncommon, Aspergillus sinusitis is related to the immune status and immunologic response of the host. A. Signs and Symptoms. In the severely immunosuppressed or neutropenic patient, Aspergillus sinusitis or rhinosinusitis may occur. Symptoms include headache, toothache, nasal congestion, purulent nasal discharge, and sinus or eye pain. Fever is commonly encountered. The nasal mucosa may exhibit hyperemia or necrosis that may extend into the mouth. Ptosis and loss of extraocular eye movement are prominent signs, indicating extensive invasion into the orbit. Sudden onset of blindness may occur. In patients with normal immune status and a …

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Farmer’s Lung

Farmer’s lung, also known as extrinsic allergic alveolitis or hypersensitivity pneumonitis, is an allergic inflammatory reaction induced by inhalation of Aspergillus spores, often in exposure to mold and hay. It usually occurs after inhalation during an overwhelming exposure to spores. A multitude of other antigenic stimuli can induce a similar syndrome. Other examples of hypersensitivity pneumonitis induced by Aspergillus include compost lung, tobacco worker’s disease (from mold on tobacco leaves), and malt worker’s lung (from moldy barley). Clinical Findings A. Signs and Symptoms. Symptoms include cough and shortness of breath, which generally develop 6-8 h after exposure. On occasion, fever and chills may be present. The presentation tends to be acute, …

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Aspergilloma

An aspergilloma of the lung may develop in individuals who have preexisting cavitary lung disease caused by conditions such as tuberculosis, sarcoidosis, silicosis, or bronchiectasis. Also known as a fungus ball or mycetoma, aspergillomas can be regarded as heavy Aspergillus colonization of the preexisting cavity. Clinical Findings A. Signs and Symptoms. The most common symptom is hemoptysis, and, on rare occasions, severe or fatal hemoptysis can develop. Other symptoms are usually related to the underlying lung disease. B. Laboratory Findings. Patients with an aspergilloma of the lung typically have elevated IgG levels specific for Aspergillus spp. Sputum smear may show the presence of filamentous fungi, and culture is intermittently positive for …

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Invasive Pulmonary Aspergillosis

Invasive pulmonary aspergillosis in the immunocompromised host is among the most serious manifestations of disease caused by Aspergillus spp. Key risk factors for invasive aspergillosis include neutropenia, especially profound neutropenia (< 100 neutrophils/mL) and prolonged neutropenia (> 12 days); prolonged high-dose corticosteroid therapy, graft-versus-host disease after bone marrow transplantation, acute rejection after solid-organ transplantation, cytomegalovirus disease after transplantation, advanced AIDS, and poorly controlled diabetes mellitus. On very rare occasions, invasive pulmonary aspergillosis may occur in previously healthy adults or in patients with alcoholic liver disease. Chronic necrotizing aspergillosis is an indolent form of invasive pulmonary aspergillosis that occurs in patients who are less profoundly immunosuppressed than those with the risk factors …

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Cryptococcus Neoformans

Essentials of Diagnosis Routine laboratory tests often normal. One-third of patients are afebrile. Definitive diagnosis made by fungal culture maintained at 37°C for 6 weeks. Cryptococcal antigen 95% sensitive in CNS infection in centrifuged CSF. India ink examination positive in only 50% of meningoencephalitis cases. CSF lymphocytes often low in CNS infection, especially in AIDS patients. Cryptococcal antigen most sensitive detection method in serum. Chest radiograph variable — multiple areas of infiltration in lower lobes most common in pulmonary disease. Molecular detection by PCR might soon become laboratory standard. General Considerations A. Epidemiology and Ecology. Cryptococcus neoformans exists as two distinct varieties known as variety neoformans and variety gattii (Table 1). …

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Candida Species

Essentials of Diagnosis Characteristic appearance of yeast and hyphae on KOH preparations. Formation of germ tubes in serum is presumptive diagnosis for Candida albicans. Cultures must be interpreted with caution because positive culture may represent colonization rather than infection. Serology not useful. General Considerations A. Epidemiology. Candida organisms are commensal with humans and, in the absence of alterations in host defense mechanisms, usually do not cause disease. Candida exists as normal flora within the oral cavity, throughout the gastrointestinal (GI) tract, in expectorated sputum, in the vagina, and in the bladder of patients with indwelling catheters. There are >150 species within the genus Candida, although the majority are not known to …

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Candidemia & Disseminated Candidiasis

Candidemia may present in a variety of fashions, ranging from asymptomatic to fulminant sepsis. The candidemic patient generally has risk factors for infection, such as malignancy, chemotherapy-induced neutropenia, organ transplantation, GI surgery, burns, indwelling catheters, or exposure to broad-spectrum antibiotics. Disseminated candidiasis must be assumed to be present in those with positive blood cultures, although negative cultures do not preclude the possibility of disseminated disease. Dissemination usually manifests with many microabscesses involving multiple organs, especially the liver, spleen, and eye, but almost any organ may be involved (Box 2). Diagnosis Candidemia is diagnosed by recovering Candida species in blood culture. Candidemia may be isolated or may occur in the setting of …

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Candiduria, Candida Cystitis & Urinary Tract Candidiasis

The presence of Candida spp. in the urine is common and does not necessarily represent infection. Candiduria is commonly associated with antibiotic use, indwelling urinary catheters, and diabetes mellitus and frequently resolves if predisposing factors can be corrected. Patients are generally asymptomatic, although some will have symptoms similar to bacterial cystitis, with dysuria, frequency, and urgency (Box 2). Urinalysis shows fungal elements and may reveal pyuria. At cystoscopy, the mucosa of the bladder typically has an inflamed appearance with adherent white plaques that may be removed with the scope. Candida spp. may also cause urethritis, typically in male sexual partners of women with vaginal Candida infection, as well as higher urinary …

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