What is the first line treatment for severe or disseminated Histoplasmosis?

Severe or disseminated Histoplasmosis is typically treated with Amphotericin B as the first-line option. This antifungal agent is a polyene that is effective against a wide range of fungal pathogens, including Histoplasma capsulatum, the organism responsible for this infection. Amphotericin B works by binding to ergosterol in the fungal cell membrane, leading to increased permeability and ultimately cell death.

In cases of severe histoplasmosis, particularly when patients are severely ill or have compromised immune systems, Amphotericin B is preferred due to its potency and rapid action. It is the drug of choice for initial treatment because it can effectively reduce the fungal burden, especially in life-threatening situations.

Other options listed, such as Itraconazole and Fluconazole, are effective for less severe, non-disseminated forms of Histoplasmosis and are generally used for maintenance therapy after initial treatment with Amphotericin B. Flucytosine may be used in combination with other antifungals but is not typically a first-line treatment. Therefore, understanding the severity of the infection and the need for aggressive treatment is key to recognizing why Amphotericin B is chosen as the first-line therapy in these cases.