There can be many causes of your sensitivity. It could be allergy based although IgE mediated allergies usually involve respiratory symptoms, but not always.
Another thought to consider is a digestive problem - lack of digestive enzymes, the high fat content of peanut butter, gal bladder issues...
You should see your doctor for an accurate diagnosis. You may need allergy testing to rule out a true allergy. You may have been tested in the past, but allergies change. It is possible.
I hope that helps you.
God bless.
Hello and hope you are doing well.
It could indicate an allergic reaction. More so if repeated episodes have occurred with consumption of peanut butter. Allergic reactions are mediated by IgE antibodies, which are released on exposure to a particular allergen. These in turn activate mast cells and lead to a local response or systemic anaphylaxis. Antihistamines may help to relieve the symptoms. It may help to maintain a food dairy and keep monitoring your symptoms. This will help to narrow the search and avoid them. Alternatively an allergy specialist may try to identify the offending allergen and try to desensitize you.
Hope this helped and do keep us posted.