For me it was measles that was the worst case. It was the 'red' measles, and probably I caught it at school, since I was the first one in the family to come down with it. But I remember one vaguely weird night, probably coinciding with my mother's report that my fever reached 108° F. And, of course, I had to stay in a darkened room for the duration: no books, no pictures.
I remember that my sister had measles, too. We didn't have whooping cough too badly; it was the little boy down the street who had that first. I wasn't very sick with scarlet fever, but the babies were (yet signs of the problems that later afflicted my brother had surfaced earlier). Even my mother got scarlet fever. After realizing that he was liable to get it, my father had to live with my grandparents across town and after the incubation period had elapsed, and he hadn't come down with it (but some of us had), he had to stay there, but could return to work. It took a while before the last of the 4 children and my mother came down with it, so we were quarantined, seeing no outsiders but the public health nurse and with the perimeter of our property marked for Scarlet Fever and forbidding access, for four weeks at least. It was fever that was dangerous, so far as I know. It was already a rare communicable disease, thanks to Louis Pasteur. Much later, when I got the opportunity to eat clotted cream from my other grandfather's own cow, I knew why people who knew it were so fond of raw milk: it is sweeter and, in a word, delicious. But not worth getting scarlet fever. Even though the rash was not so dangerous, it did itch. It just occurred to me to go to the Wiki to find out something about it, since all I know is what I experienced more than a half century ago.
Anyhow, when it was over, the Public Health nurse wanted all our toys, including books, destroyed by burning. Though I didn't always agree with my mother's taking stands on things, I did agree with her this time. She refused. The nurse retreated and said that it would suffice to put everything out in full sunlight all day, provided it was a clear warm day. This we did, and the only thing that had to be replaced was crayolas, which melted.
Are families still quarantined? I can't remember an instance, firsthand.
My sister and I both had suffered from tonsillitis, and I was diagnosed with adenoids as well, and we were hospitalized for their removal. I was 8 years old, so it was between my birthday in June, 1942 and our moving to the S.F. Bay Area in October. I remember ether anaesthesia. I remember spitting blood and being given ice cream for food and aspergum to chew for the discomfort. I don't think tonsillectomies were done in the doctor's office then (but neither were they yet routinely removed, just in case they got infected), even without adenoids as well. I think that medicine since has found that tonsils are useful for getting infected and preventing more serious things? I don't know We both were in the hospital for several days.
P.S. I was right about tonsils: not useless. As for scarlet fever, neither I nor those who cared for us knew anything. Just google it for yourselves.
As for raw cream, NOT.
As for treatment: there were no antibiotics, no sulfa, no penicillin, none of the rest. My mother was right to take a stand, though, but a couple of hours of California sunlight would have sufficed.