How did they diagnose the folliculitis?

Just to keep in the (very far) back of your mind -- if treatments for folliculitis don't end up working, you might want to have them rule out pemphigus.

I take Mestinon for an autonomic problem and stumbled upon a few interesting diseases/conditions treated with it (and that is one of them). While pemphigus is pretty rare, there are a few case reports of it occurring with myasthenia gravis (you can google that because I can't post links yet) and it can present as pustules (you can look up pustules and pemphigus). I don't know what medications you're on for myasthenia gravis ... with the above condition, some of same meds might treat both (and I'm sorry for sneaking into this forum but I do now and then because a few people with what I have have myasthenia gravis and I find the connection interesting).