Oral histoplasmosis without pulmonary involvement: an uncommon condition in children

Abstract

Background: The present study aims to report an unusual case of Histoplasma capsulatum infection with oral lesion, without pulmonary involvement. Case Presentation: This report presents a 9-year-old male patient who was admitted to a hospital in Itanhaém with a history of an ulcerative lesion in the oral mucosa for 2 months. After investigation, histoplasmosis was confirmed through biopsy, and treatment with Itraconazole was initiated for 90 days. A chest computed tomography (CT) was also requested to exclude pulmonary involvement. Conclusions: Histoplasmosis primarily presents with pulmonary involvement, and oral mucosal manifestations are rare, which may indicate advanced dissemination. This uncommon clinical form may contribute to underdiagnosis. The gold standard for diagnosis is the isolation of H. capsulatum from secretion or tissue samples. Imaging studies such as chest X-ray, CT scan, and Magnetic resonance imaging (MRI) are helpful in the diagnostic investigation. The severity of the disease is associated with the patient's immune status, and in mild cases, an expectant approach may resolve the condition. However, antifungal therapy is necessary to prevent dissemination or to treat mild to intermediate cases, with Itraconazole being the drug of choice. In more severe cases, liposomal Amphotericin B may be used. Therefore, it is essential to consider this differential diagnosis of oral mucosal lesions in order to reduce underreporting of cases and to enable earlier diagnosis, improving the resolution of future similar cases.