A probable case of histoplasmosis presenting as portal hypertension and bone lesion in a case of common variable immunodeficiency syndrome

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Paediatric Histoplasmosis 2000-2019: A Review of 83 Cases

Histoplasmosis is an endemic fungal infection that is confined to specific geographical regions. Histoplasma spp. are primary pathogens that cause disease in both immunocompetent and immunocompromised patients, ranging from a single-organ (mostly affecting the lungs) infection to life-threatening disseminated disease. Knowledge about the clinical epidemiology relies on data from adult populations; little is known about the patient and disease characteristics in the paediatric population. Therefore, a structured review of published cases of paediatric histoplasmosis between 2000 and 2019 was performed. A literature search of PubMed was conducted and the epidemiological and clinical data from 83 cases were analysed. The mean age at presentation was 9.5 ± 5.5 years, and 51% were girls. Two-thirds of the children were immunocompromised. The majority of children presented with disseminated disease. The most frequently observed clinical symptoms were respiratory symptoms, alongside non-specific systemic features, including fever, myalgia, fatigue and weight loss. The mortality rate was 11%. Histoplasmosis affects children of any age. Being immunocompromised is a risk factor for severe and disseminated disease. The lack of specific presenting features leads to underreporting and delay in diagnosis. To improve the recognition and outcome of histoplasmosis in childhood, increased awareness and surveillance systems are warranted.

A case of Histoplasma capsulatum variety capsulatum septic arthritis successfully treated with surgery, systemic antifungals, and local amphotericin cement beads

Histoplasma capsulatum variety capsulatum (H. capsulatum) is a thermally dimorphic fungus that is endemic to the Mississippi River and Ohio River valley regions. Of the hundreds of thousands of patients exposed to this fungus, less than 1% develop a severe illness most commonly manifesting as pulmonary disease. Septic arthritis from hematogenous seeding with H. capsulatum or from direct inoculation has been reported only rarely in the literature. The first case of septic arthritis of the shoulder due to H. capsulatum occurring in an immunocompromised patient, treated successfully with irrigation and debridement, systemic antifungals, and local delivery of amphotericin B with cement beads, is reported here. Importantly, the addition of local amphotericin B delivery by cement beads to conventional treatment likely led to clinical cure in this patient.

Disseminated histoplasmosis in a patient with common variable immunodeficiency: A coincidence or the result of T cell defects?

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T cell defects can be significant in common variable immunodeficiency.

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Abnormal T cell activation in common variable immunodeficiency can cause massive splenomegaly.

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Disseminated histoplasmosis can occur in common variable immunodeficiency as a result of such T cell defects.

Background

In endemic regions, histoplasmosis is often seen in hosts with defective cell mediated immunity. We report a case of disseminated histoplasmosis in a patient with common variable immunodeficiency (CVID), a disorder mainly characterized by B cell defects.

Case

A 35 year old male with CVID developed fever, headache, dyspnea and pancytopenia within few weeks of swimming in the Tennessee River. After a non-revealing initial evaluation he was transferred to a tertiary facility for fever of unknown origin, where massive splenomegaly was noted. Clinical course was complicated by hypoxia from extensive bilateral lung infiltrates requiring non-invasive ventilation. Urine and serum Histoplasma antigens were positive. He was treated with liposomal amphotericin B followed by itraconazole after clinical improvement within 48 h and discharged home by day 6. Fungal blood cultures sent on day 1 grew Histoplasma capsulatum on day 19. After 5 months splenomegaly completely resolved and he successfully completed one year of treatment with itraconazole.

Conclusions

Our case highlights the significance of T cell defects in CVID. More research focusing on T cell defects in CVID is required to understand the extent of vulnerability to such intracellular pathogens in CVID.