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Allergic and Immunologic Reactions
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Saira N. Agarwala, Aspen R. Trautz, Sylvia Hsu
Overview: Although approximately 30–50% of cases have no identifiable underlying cause, EN is known to occur secondary to a variety of conditions. The most common causes of secondary EN include streptococcal infections, viral upper respiratory tract infections, bacterial gastroenteritis, coccidiomycosis, medications, and systemic diseases, such as sarcoidosis, tuberculosis, and inflammatory bowel disease. EN is more prevalent in women who are 20–40 years old. Additionally, it is more often seen in areas where certain predisposing infections, such as Coccidioides immitis, are more commonly encountered.
The Fungi
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Coccidioidomycosis is caused by the dimorphic fungus, Coccidioides immitis. This agent is endemic in the southwestern United States, an area characterized by a hot, dry climate. Mycelial growth occurs in rodent burrows where the soil is moist and enriched by animal droppings. After periods of heavy rains the arthroconidia, formed by fragmentation of the hyphae, are carried to the surface and aerosolize upon drying. Arthroconidia are the infectious units which are inhaled by the host. Upon entry into the lung, phase transformation to a spherule takes place. Spherules grow to large sizes, 20 to 80 μm in diameter. Cytoplasmic reorganization occurs within the spherules resulting in the formation of hundreds of endospores, 3 to 4 μm in diameter, which are released upon rupture of the spherule. Each endospore develops into another spherule, thus, continuing the cycle.
Coccidioides
Published in Rossana de Aguiar Cordeiro, Pocket Guide to Mycological Diagnosis, 2019
Coccidioidomycosis is a deep-seated infection caused by two dimorphic fungal species: Coccidioides immitis and C. posadasii. Apparently, both species have similar phenotypical and virulence traits, and may cause severe infections with common signs and symptoms. The disease occurs only in the Americas, primarily in areas situated between the north and south 40° latitudes, and the great majority of cases have come from the United States (Hector & Laniado-Laborin, 2005). However, each species shows a specific pattern of distribution: C. immitis occurs in central and southern California, and C. posadasii occurs in the US states of Nevada, Arizona, New Mexico, and western Texas, as well as in Mexico and Central and South America (Kirkland & Fierer, 2018). Coccidioides spp. are found in soils of desert, arid, or semi-arid areas, where they grow saprophytically in the filamentous form. In nearly all cases, the infection results from the inhalation of conidia produced during the filamentous phase, after deliberately stirring the soil—agriculture, hunting, well digging, etc.—or due to environmental disturbances such as sandstorms and earthquakes (Schneider et al., 1997).
Treatment of infections in cancer patients: an update from the neutropenia, infection and myelosuppression study group of the Multinational Association for Supportive Care in Cancer (MASCC)
Published in Expert Review of Clinical Pharmacology, 2021
Bernardo L. Rapoport, Tim Cooksley, Douglas B. Johnson, Ronald Anderson, Vickie R. Shannon
Both the duration (>1 week) and severity (<100 cells/μl) of neutropenia influence the risk of fungal pneumonia [105,106]. Hence, infections caused by gram-negative bacterial pathogens predominate during the early (less 7 days) neutropenic period, while fungal infections caused by Aspergillus, Zygomycetes, and Fusarium spp are common as neutropenia persists beyond 1–2 weeks. The spectrum of pulmonary fungal infections in neutropenic patients includes members of the invasive Aspergillus spp, the non-Aspergillus molds (Scedosporium spp, Fusarium spp, Pseudallescheria boydii), Mucorales spp and the dematiaceous molds [107]. Aspergillus spp, particularly A. fumigatus, is the most frequently identified fungal organism in neutropenic patients. A. niger, A. flavus, and amphotericin- and azole-resistant mold infections have also emerged as important pathogens in this setting [108–110]. Mixed infections with fungal species and respiratory viruses, cytomegalovirus (CMV), and/or gram-negative bacilli are also common. Recent declines in pneumonia caused by endemic fungi, including Histoplasma capsulatum, Coccidioides immitis, and Blastomyces dermatitidis, have been attributed to the use of fluconazole prophylaxis in hematologic malignancies and following HSCT as the standard of care. Rates of Pneumocystis jirovecii pneumonia have declined significantly with the use of trimethoprim-sulfamethoxazole prophylaxis during the neutropenic period after HSCT [111,112].
Cutaneous coccidiomycosis presenting with a facial plaque
Published in Baylor University Medical Center Proceedings, 2019
Coccidiomycosis, or “valley fever,” is caused by the virulent, dimorphic, soil-dwelling fungus Coccidiodes immitis. Endemic areas include the southwestern USA, northern Mexico, and Central and South America. Infection typically occurs via inhalation of arthroconidia and most commonly results in pulmonary disease.1–6 Presenting symptoms can include cough, fever, and arthralgias, although up to 60% of patients are asymptomatic. Disseminated disease occurs in up to 5% of patients.5–7 Filipinos, blacks, pregnant women, and immunosuppressed patients are at increased risk for developing widespread disease.1–6 Skin involvement by coccidiomycosis can present as papules, pustules, plaques, nodules, abscesses, or ulcerations and is seen in up to 50% of symptomatic patients.2–4,6,8,9 In addition, coccidiomycosis can cause hypersensitivity reactions such as erythema nodosum and erythema multiforme.2–4,9 Though any anatomical site may be affected, the head and neck are most commonly affected.3,6 Cutaneous involvement most often results from disseminated disease. Here, we present a patient with coccidiomycosis presenting with a facial plaque.
Advances in the diagnosis of fungal pneumonias
Published in Expert Review of Respiratory Medicine, 2020
Bryan T. Kelly, Kelly M. Pennington, Andrew H. Limper
Coccidioidomycosis is an infection caused by the endemic fungi Coccidioides immitis and Coccidioides posadasii primarily found in the southwest region of the United States and northwestern Mexico [6]. Pulmonary infection is often asymptomatic or mildly symptomatic presenting similar to community-acquired pneumonia. A small number of patients may develop more severe disseminated infection. Patients at increased risk for disseminated infection include immunocompromised patients, pregnant patients, and those of Filipino and African descent, though reasons behind increased dissemination on a racial basis remain unclear [6].