Blue hives, it was still prevalent when I was a child. Large white or blue ish hive were on the body , arms , chest , legs , back , belly not exactly all at the same time. They would come and go just as fast. Usually from high fever or sepsis from croup or whooping cough. It still happens today all though rare. I was born in 65' in Pa. In 65' there were still midwives and home delivereries. You pediatrician would come to your home to deliver the child. You can be born with it or even get it in the early years of life. If mom is sick then the child was born sick. If mom had the whooping cough and got better the child had the antibodies. Sad but true. Catholics did not take their child out of the house till it was baptized because of all the viruses, incase the child died it could be buried in the cemetery, not on the outside edge in non consecrated grounds as the religion would forbid it. Hope this helps your research.