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

Synovitis due to Histoplasma capsulatum: a case series and literature review

Musculoskeletal manifestations of Histoplasma capsulatum infection are uncommon but can mimic inflammatory arthritis. Early diagnosis of this complication is of critical importance in the era of potent immunosuppression for rheumatologic diseases. We conducted a retrospective chart review for patients with histoplasmosis and tenosynovitis, synovitis, or arthritis, diagnosed and treated at our institution between January 1, 2000, and December 31, 2019. We also reviewed the relevant literature. Four patients with biopsy-proven, culture-proven histoplasma tenosynovitis were identified at our institution. All four patients had wrist or hand involvement in an asymmetric pattern, and one patient had lower extremity involvement as well. Two patients were not immunocompromised at baseline. One patient underwent a lengthy evaluation and received immunosuppression for 4 years without improvement prior to the diagnosis of histoplasmosis. Histoplasma serologic tests varied among patients with localized infection. Pathologic findings revealed non-caseating granulomatous inflammation. Three patients recovered after 6-12 months of antifungal treatment. One patient still had recurrent infection despite 20 months of treatment. Histoplasma tenosynovitis and synovitis are rare causes of inflammatory arthritis. Infectious causes should be considered and carefully evaluated when patients present with asymmetric oligoarthritis. Early recognition is crucial for successful treatment, especially in patients with concomitant rheumatologic diseases receiving immunosuppressive treatment.

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.

Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

The administration of approved antifungals via unapproved formulations or administration routes (such as aerosol, direct injection, irrigation, topical formulation and antifungal-impregnated orthopedic beads or cement) may be resorted to in an attempt to optimize drug exposure while minimizing toxicities and/or drug interactions associated with conventional (systemic) administrations. Existing data regarding such administrations are mostly restricted to uncontrolled case reports of patients with diseases refractory to conventional therapies. Attribution of efficacy and tolerability is most often problematic. This review updates prior published summaries, reflecting the most recent data and its application by available prevention and treatment guidelines for invasive fungal infections. Of the various dosage forms and antifungals, perhaps none is more widely reported than the application of amphotericin B-containing aerosols for the prevention of invasive mold infections (notably Aspergillus spp.).

Upper extremity Histoplasma capsulatum treatment with isavuconazole

Extrapulmonary Histoplasma capsulatum infections in the immunocompetent population are rare and pose a diagnostic challenge. Upper extremity histoplasmosis without a primary lung infection is uncommon. It is possible to acquire it by inadvertent trauma with direct inoculation.

Our case describes an immunocompetent patient with progressive swelling with minimal pain in the wrist associated with a small puncture wound on the left dorsal forearm. The initial workup failed to identify a specific etiology. For the following six weeks, the patient experienced progressive worsening of symptoms, warranting a referral to an orthopedic

hand surgeon. Left lower extremity magnetic resonance imaging (MRI) findings were non-specific.

The surgeon performed a surgical exploration and debridement with the excision of hypertrophic tissue. Initial stains showed a granulomatous tissue but did not reveal an organism; however, a month later, mold was identified on the growth medium. The patient was initiated in isavuconazole empiric therapy. Four weeks later, a matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) confirmed the diagnosis as Histoplasma capsulatum. The patient had clinical remission with isavuconazole used as the United States Food and Drug Administration (FDA) off label use.