Overuse of Steroid Infusions/ER Visits?

Hello,
I am new to being a caregiver and new to MS. My boyfriend of almost 2 years was diagnosed with MS 4 years ago. I go to all of his appointments (neurologist, MRI's, etc,) and have spent many nights sleeping in the hospital when he has had a flare up. Being that his next appointment is not until next month, I wondered if anyone could help out with a question. How often is too often to go to the ER for a steroid infusion? It seems that every time my BF has a flareup he immediately goes to the ER to request a steroid infusion. Everything I have read and heard from doctors is that you should wait 24 hours to see if symptoms go away on their own. He has been admitted to the ER for infusions at least 6 times this past year.
About two weeks ago he was diagnosed with the flu, double ear infection and an upper respiratory infection. He started having MS exacerbations and wanted to immediately go to the ER for steroid infusions. I had read that when you have MS and get the flu, you will have MS-like symptoms because your immune system is shot and is working really hard to fight the virus. I called his neurologist and she said that it would be a bad idea to get a steroid infusion due to his lowered immune system and unfortunately had to let the meds run their course. The only reason she gave to go to the ER was if he was experiencing new symptoms or was in a very weakened state. He did not complete his round of antibiotics (grrr) and today started to have symptoms again. It was also quite warm today, so I asked him to go sit in air conditioning to see if he felt better and offered to call his neurologist. He did not want to me to call his neurologist, so he sat and relaxed a bit. His symptoms have subsided and he is now sleeping.
I want to honor his pain and discomfort, but I also am unaware of how often is too often or what is a "safe" exposure to steroids. Of course I will ask at his appointment next month, but wondered if anyone had any insight they could provide.
Thank you!