Disseminated histoplasmosis presenting as bilateral lower extremity paresis

Disseminated histoplasmosis from western Mexico-rethinking our geographic distribution of endemic fungal species: a case report and review of literature

BACKGROUND

Histoplasma is a fungal pathogen found in many parts of the world. In North America, its distribution is traditionally thought to be endemic to the Ohio and Mississippi River valleys. Development of histoplasmosis after Histoplasma exposure is related to degree of inoculum exposure and susceptibility, for example, immunocompromised status. Most exposed, healthy individuals are asymptomatic and few develop pulmonary symptoms. A limited number of infectious etiologies (that is, Histoplasma, Coccidioides, and Mycobacterium tuberculosis) can cause miliary pattern on chest imaging, and thus, histoplasmosis should be considered whenever a patient presents with pulmonary symptoms and these unique radiographic findings.

CASE PRESENTATION

A previously healthy 13-year-old Hispanic male presented as a transfer from an outside hospital with fever and hypoxia in the setting of a progressive, subacute gastrointestinal illness. Given hypoxia, the concern for sepsis, and unclear etiology of his illness, broad-spectrum antimicrobial therapy and noninvasive ventilation were started. Initial evaluation demonstrated miliary pulmonary infiltrates, and travel history raised suspicion for coccidioidomycosis or tuberculosis. After a complete evaluation, lab studies confirmed a diagnosis of histoplasmosis, and the patient made a full recovery after the initiation and completion of antifungal therapy.

CONCLUSION

Herein, we present a patient who acquired histoplasmosis from an area of Mexico not currently acknowledged as endemic and review recently published data emphasizing new areas of Histoplasma endemicity in North America, particularly the southwest USA and most states of Mexico. Though limited surveillance data exist, mounting case reports/series and local epidemiologic studies illustrate the expanding worldwide endemicity of Histoplasma and underscore histoplasmosis as a growing global health concern.

Epidemiological, clinical, diagnostic, and therapeutic features of histoplasmosis: A systematic review

Histoplasmosis is a mycosis due to a dimorphic fungus Histoplasma capsulatum. This study aimed at providing an overview of histoplasmosis epidemiological, clinical, diagnostic, and therapeutic aspects from the last 30 years. This review was carried out using a systematic literature search on histoplasmosis from 1992 to 2021. We describe the clinical features, diagnostic methods and treatment. Empirical searches were conducted via the databases PubMed, Google Scholar and Science Direct. Between 1992 and 2021, 190 manuscripts were published and reported 212 cases of histoplasmosis. These publications included 115 and 97 cases of American and African histoplasmosis respectively. The number of publications increased over the last ten years with a maximum in 2020 (12.34 % of the cases reported). The disseminated forms of histoplasmosis were the most frequently reported cases as compared to the localized forms. This was the case with the American histoplasmosis (75.65 %) as well as with the African histoplasmosis (55.67 %). Itraconazole (31.17 %) and Amphotericin B (26.62 %) were the most used drugs in the management of these cases. American histoplasmosis is distributed worldwide whereas African histoplasmosis is mainly present in intertropical Africa. There is a critical need for setting up a global surveillance system, towards a better understanding of the disease.

Endemic Fungal Infective Endocarditis Caused by Coccidioides, Blastomyces and Histoplasma Species in the United States

We describe a recent case of Coccidioides bioprosthetic aortic valve infective endocarditis successfully managed at our institution. This led us to perform a literature review of endemic fungal infective endocarditis in the United States caused by Coccidioides, Blastomyces, and Histoplasma. Symptoms preceded infective endocarditis diagnosis by several months. Patients with Coccidioides and Blastomyces infective endocarditis were younger with fewer comorbid conditions. Valvular involvement was relatively uncommon in Blastomyces infective endocarditis (27%). Fungemia was noted in patients with infective endocarditis due to Histoplasma (30%) and Coccidioides (18%). Mortality rates for infective endocarditis were high (Histoplasma, 46%; Coccidioides, 58%; Blastomyces, 80%); infective endocarditis was commonly diagnosed post-mortem (Coccidioides, 58%; Blastomyces, 89%). Most surviving patients with infective endocarditis (Histoplasma, 79%; Coccidioides, 80%) underwent valve surgery along with prolonged antifungal therapy. The two surviving patients with Blastomyces infective endocarditis received antifungal therapy without surgery.

Infectious Myelitis

Myelitis is an extensive group of pathologies, including inflammatory, demyelinating, and infectious disorders, sometimes mimicking tumors. This article will discuss infectious myelitis, mainly the patterns of spinal cord involvement caused by each infectious agent and the contribution of magnetic resonance imaging as a major tool to establish the specific diagnosis.

Intramedullary histoplasmosis of the thoracic cord as an isolated lesion: A rare case report and literature review

Background

Disseminated histoplasmosis involving the central nervous system occurs in 5-10% of cases. However, intramedullary spinal cord lesions are extremely rare. Here, 45-year-old female with a T8-9 intramedullary lesion did well following surgical extirpation.

Case Description

For 2 weeks, a 45-year-old female experienced progressive lower back pain, paresthesias, and paraparesis. The magnetic resonance imaging showed an intramedullary expansive lesion at the T8-T9 level that markedly enhanced with contrast. Surgery, consisting of T8-T10 laminectomies performed using neuronavigation, an operating microscope, and intraoperative monitoring, revealed a well-demarcated lesion that proved to be a focus of histoplasmosis; it was readily completely excised.

Conclusion

Surgery is the gold standard for treating spinal cord compression attributed to intramedullary histoplasmosis unresponsive to medical management.

Intramedullary histoplasmosis lesion in children: A case report

Background:

Histoplasmosis is a fungal disease endemic in some regions of the United States of America, Canada, and Latin America. The geographic characteristics, humidity, soil, and climate are responsible for such distribution. In Brazil, there are case reports of histoplasmosis throughout its territory, being considered an endemic region. It is considered an opportunistic disease, affecting mostly immunocompromised patients. To the present date, scientific publications dealing with pediatric cases of histoplasmosis are restricted to case series. Spinal cord injuries caused by histoplasmosis are rare, even in the adult population, being described in few studies.

Case Description:

The present report deals with a 4-year-old patient, from the southeast region of Brazil, who started a condition of fever, weight loss, cervicobrachialgia, and symmetrical tetraparesis, with evolution over 2 months. In the diagnostic investigation, she was found to have primary immunodeficiency and neuroimaging examinations showed a cervical spinal cord lesion at the level of C4-C6. The anatomopathological diagnosis of histoplasmosis was possible after surgery for decompression and biopsy of the lesion.

Conclusion:

According to our research, there are no reports in the literature that address the situation of spinal cord compression syndrome due to histoplasmosis in the pediatric population.

Indolent nonendemic central nervous system histoplasmosis presenting as an isolated intramedullary enhancing spinal cord lesion

Background

Histoplasma capsulatum infection is largely seen in endemic regions; it results in symptomatic disease in <5% of those infected and is most often a self-limiting respiratory disease. Disseminated histoplasmosis is considered rare in the immunocompetent host. Central nervous system (CNS) dissemination can result in meningitis, encephalitis, and focal lesions in the brain and spinal cord, stroke, and hydrocephalus. An intramedullary spinal cord lesion as the only manifestation of CNS histoplasmosis has been rarely described.

Case Description

We present an atypical case of a 44-year-old man from a nonendemic region, on adalimumab therapy for ulcerative colitis who developed an isolated intramedullary spinal cord lesion in the setting of disseminated histoplasmosis. His course was initially indolent with vague systemic symptoms that led to consideration of several other diagnoses including sarcoidosis and lymphoma. Biopsies of several positron emission tomography positive lymph nodes revealed granulomatous inflammation, but no firm diagnosis was achieved. He was ultimately diagnosed with histoplasmosis after an acute respiratory infection in the setting of anti-tumor necrosis factor therapy. With appropriate antifungal therapy, the spinal cord lesion regressed. The previous systemic biopsies were re-reviewed, and rare fungal elements consistent with H. capsulatum were identified. A presumptive diagnosis of CNS histoplasmosis was made in the absence of direct laboratory confirmation in the setting of rapid and complete resolution on antifungal therapy.

Conclusion

Disseminated histoplasmosis should be considered in granulomatous disease, even if the patient resides in a nonendemic region. Furthermore, clinicians should be mindful that CNS histoplasmosis may present in an atypical fashion.