MYCOLab Ai Logo - gold and army green

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

Summary

A 28-year-old woman developed a fungal infection called histoplasmosis after having a tooth extracted, with the infection spreading to her lungs and sinuses. She was initially given a common antifungal medication called itraconazole, but her condition continued to worsen despite increasing the dose. When doctors switched her to a stronger medication called liposomal amphotericin B given intravenously, she improved dramatically and recovered fully. This case shows the importance of recognizing when a standard fungal treatment is not working and switching to more aggressive therapy.

Background

Histoplasmosis caused by Histoplasma capsulatum typically presents as pulmonary infection but can disseminate, with oral lesions being common in immunocompromised individuals. However, disseminated histoplasmosis with oral lesions is rare in immunocompetent patients. Itraconazole is the preferred treatment for mild cases while liposomal amphotericin B is used for severe forms.

Objective

This case report aimed to describe a 28-year-old immunocompetent female who developed disseminated histoplasmosis following dental surgery and oroantral fistula. The case highlights the importance of recognizing treatment failure and adjustment of therapy when itraconazole proves inadequate.

Results

Despite itraconazole therapy (200 mg twice daily, increased to 600 mg), the patient’s condition deteriorated with disease progression on imaging. Therapeutic drug monitoring showed subtherapeutic levels initially, then therapeutic levels, but clinical response remained poor. Switching to six weeks of intravenous liposomal amphotericin B led to marked improvement, resolution of lung nodules, negative antigen testing, and full recovery with subsequent 12-month itraconazole maintenance therapy.

Conclusion

This case emphasizes the need for strong clinical suspicion of histoplasmosis to avoid misdiagnosis and demonstrates the challenges of itraconazole therapy including drug monitoring and efficacy. The favorable response to liposomal amphotericin B after itraconazole failure highlights the importance of individualized treatment plans and consideration of alternative antifungal agents in refractory cases.
  • Published in:Current Medical Mycology,
  • Study Type:Case Report,
  • Source: PMID: 41122116, DOI: 10.22034/cmm.2025.345248.1613
Scroll to Top