Beware of hairy yellow caterpillars with black spikes. They are American dagger moths that have have toxic properties when hairs are touched. One slight brush sent me to the ER with significant hives, elevated blood pressure, facial flushing, and chills.
I did some online research and learned that pets who innocently consume the caterpillars can also become ill enough to seek a vet's care. I am still afflicted with hives after three days and am dosing with Benedryl. One helpful hint is applying ice directly on hives and it has helped when topical cortisone and oral medications have fallen short relieving the itching.
You can Google search a photo and info about American Dagger moth and other toxic hairy caterpillars all over the US. I also found many other home remedies for hives.
By Kathy from Western PA