What is the first line treatment for Blastomycosis with severe central nervous system involvement?

The first line treatment for Blastomycosis with severe central nervous system involvement is Amphotericin B due to its efficacy in addressing serious fungal infections. Blastomycosis is caused by the fungus Blastomyces dermatitidis, which can lead to disseminated infections, including those affecting the central nervous system (CNS).

Amphotericin B is a polyene antifungal agent that works by binding to ergosterol in the fungal cell membrane, creating pores that lead to cell death. It is typically reserved for severe infections because it is highly effective but can also be associated with more significant side effects. In cases of CNS involvement, the ability of Amphotericin B to penetrate the blood-brain barrier and achieve therapeutic concentrations is crucial, making it a preferred choice.

Itraconazole and fluconazole are often used for less severe infections or for maintenance therapy after an initial response to Amphotericin B. They may not have the same level of efficacy in treating advanced or disseminated disease with CNS involvement. Nystatin primarily treats mucosal fungal infections and is not suitable for systemic infections like Blastomycosis. Thus, Amphotericin B stands out as the most appropriate first-line treatment for severe cases involving the CNS.