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Fungal Infections
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Uwe Wollina, Pietro Nenoff, Shyam Verma, Uta-Christina Hipler
Clinical presentation: Blastomycosis is caused by a dimorphic fungus endemic in soil with a high prevalence in the Midwest of the United States. The asexual form is known as Blastomyces dermatitidis, while the sexual phase is called Ajellomyces dermatitidis. Primary cutaneous blastomycosis is rare, while secondary spread to the skin by pulmonary blastomycosis is seen in up to 30% of patients. North American cutaneous blastomycosis typically evolves from papules that develop into crusted, vegetative plaques often with central clearing or ulceration. Lymphangitis and lymphadenopathy may be present. It occurs also in immunocompetent patients and can be diagnosed by culture, direct visualization of the yeast in affected tissue by silver or periodic acid Schiff (PAS) stains and/or antigen testing.
Blastomycosis
Published in Rebecca A. Cox, Immunology of the Fungal Diseases, 2020
It has been recognized for quite some time that clinically apparent blastomycosis develops in males more frequently than in females (male to female ratio, 9:1).18 It has been argued that this predilection is related to occupation and to involvement in recreational activities. Manual laborers, agricultural workers, and hunters constitute the majority of reported cases of blastomycosis. This analysis has been influenced by the fact that the aforementioned activities have been performed chiefly by males. However, blastomycosis in canines, which is clinically similar to the human disease, also develops more frequently in males than in females (3 males to 1 female),19 and there is no evidence to suggest that male canines have different environmental exposures than do females. Therefore, it seems likely that for reasons that are not yet clear, males are more susceptible to blastomycosis.
The respiratory system
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
Some of the fungi causing lung disease are purely saprophytic and grow along pre-existing cavities or necrotic lung tissue. Others, such as blastomycosis and coccidioidomycosis, are seen in well-defined geographical zones, where the fungal spores are found in the soil, and which cause primary invasive infections in previously healthy people, in the absence of predisposing factors. Clinical history of travel to or residency in these areas can help with diagnosis. Fungi cause a variety of effects from necrotizing granulomatous inflammation as in coccidioidomycosis and histoplasmosis, to allergic-type reactions, such as asthma due to absorption and sensitization to fungal products in aspergillus infection.
Endemic mycoses: epidemiology and diagnostic strategies
Published in Expert Review of Anti-infective Therapy, 2020
Andrés Tirado-Sánchez, Gloria M. González, Alexandro Bonifaz
Blastomycosis is a severe mycosis of humans and other mammals caused by thermally dimorphic and environmental fungi of the genus Blastomyces. The main agents involved include Blastomyces dermatitidis, Blastomyces gilchristii, and Blastomyces percursus [86]. The geographic risk region for blastomycosis is not fully understood, due in part to the difficulty in determining the exposure time in some patients having prolonged latency period, the absence of a skin test or other reliable marker of previous exposure, and the scarcity of cases in which B. dermatitidis (s.l.) has recovered from the environment [87]. However, blastomycosis is considered endemic to the areas surrounding the Great Lakes, the Mississippi and Ohio River valleys, and the St. Lawrence River, including many US states and provinces of Canada [88]. Endemicity is most pronounced in hyperendemic regions of north-western Ontario and north-central Wisconsin, exceeding 100 cases per 100,000 inhabitants [87]. In recent years, cases have been reported in New York, Quebec, and Saskatchewan [5].
Endemic pulmonary fungal diseases in immunocompetent patients: an emphasis on thoracic imaging
Published in Expert Review of Respiratory Medicine, 2019
Ana Luiza Di Mango, Gláucia Zanetti, Diana Penha, Miriam Menna Barreto, Edson Marchiori
Blastomycosis is an endemic fungal infection caused by the thermally dimorphic fungus, Blastomyces spp. and causes disease mostly in immunocompetent hosts, with a slight predilection for men. Although epidemiological knowledge about this disease is limited, it occurs mainly in North America, predominantly in the Mississippi and Ohio River valleys, as well in Canadian provinces that border the Great Lakes. Blastomyces is found in forested or sandy soils, with decaying vegetation located near water sources. This fungus can also grow in bird guano. Recent analysis suggests that Blastomyces genus may have two different species, B. dermatitidis and B. Gilchristii. Similar to most of the other endemic mycoses, infection occurs most commonly following inhalation of conidia that are aerosolized after soil disruption. Within alveoli, conidia convert into yeast, which is more difficult to kill by host cell immunity. Traumatic inoculation of skin is less common, but also reported. B. dermatitidis can also infects animals, mainly dogs [46–49].
Disseminated blastomycosis in coalworkers’ pneumoconiosis
Published in Baylor University Medical Center Proceedings, 2019
Utsav Shrestha, Chetan Naik, Arthur Huen, Keely Marshall, Karunamurthy Arivarasan, John McDyer
Blastomycosis is a thermally dimorphic fungi endemic to the South Central, Southeastern, and Midwest regions of the USA.1 The primary site of infection is the lungs, and it causes acute and chronic pneumonitis and, rarely, a fulminant pulmonary infection with acute respiratory distress syndrome. Infection can disseminate to extrapulmonary organs, especially skin. Although immune-competent and immunocompromised hosts can acquire the disease, the disease tends to be severe in immunocompromised hosts.2,3 Pneumoconiosis, especially silicosis, is associated with an increased risk of mycobacterial and fungal infection.4–6 We present a case of disseminated blastomycosis in a patient with coalworkers’ pneumoconiosis.