fungal and protist infections, especially those that are deeper than the skin, are especially hard to treat. why?

Answer and explanation:

Fungi and protists are eukaryotic. However, antibiotics selectively targets prokaryotic cells. Thus, the use of antibiotics for the treatment of fungal and protist infection is of no use at the first place. Secondly, if we use the other medicines that could kill the fungi/protists (e. g. fungicides), they could also kill the host's cells (animal's cells). This become further difficult if the infection is deeper in the skin. This is because, we would not be able to apply the medicine as direct application on skin but would give either intravenous or via food. This would increase the chance of imacting negatively the other organs/cells. The only option in such scenario is the surgery, which cannot be 100% effective because some spores may left even after the treatment.