# A case report of disseminated histoplasmosis not responding to primary treatment by itraconazole

## TL;DR

A 28-year-old woman with disseminated histoplasmosis did not respond to itraconazole but improved after switching to amphotericin B.

## Contribution

A rare case of disseminated histoplasmosis in an immunocompetent patient unresponsive to itraconazole is reported.

## Key findings

- The patient's condition worsened on itraconazole but improved after switching to liposomal amphotericin B.
- Lung nodules resolved and antigen testing turned negative after amphotericin B treatment.
- The case emphasizes the need for treatment adjustment in non-responders to itraconazole.

## Abstract

Histoplasmosis, caused by Histoplasma capsulatum, typically presents as a pulmonary infection but can disseminate, with oral lesions being common among immunocompromised individuals. However, this is rare among immunocompetent patients. Preferred treatments include itraconazole for mild cases and liposomal amphotericin B for severe forms.

This study aimed to report a 28-year-old female who developed disseminated histoplasmosis following a right oroantral fistula after dental surgery. It was initially misdiagnosed as
Actinomycosis; however, a positive urinary Histoplasma antigen test confirmed histoplasmosis. Despite itraconazole therapy (200 mg twice daily, later increased to 600 mg),
her condition continued to deteriorate, with disease progression seen on imaging. Switching to six weeks of intravenous liposomal amphotericin B led to marked improvement,
resolution of lung nodules, and negative antigen testing. She was discharged with a 12-month course of itraconazole therapy.

This case highlights the importance of timely recognition and adjustment of treatment in non-severe histoplasmosis, particularly for patients who do not respond adequately to itraconazole therapy.