I realize that allergies may have been significantly less common in the past due to natural section. Did they seem them as in connection to religion or witchcraft somehow? Did they understand that some substances illicit a response in certain individuals and was there a treatment?
Skin contact allergies were easily understood without resorting to supernatural explanations. As early as 1624, Rhus Radicans had gotten the nickname Poison Ivy.
The concept of poisons predates this by about 6 millenia.