i honestly think it was an allergic reaction of some sort , i think to my cat's flea n tick medicine we put on him .. because it has went away and has stayed gone. since we have not put anymore medicine on my cat.
It does sound like an allergy to a new medication or some new detergent such as dish soap, hand soap etc. I would see your doctor. Try to think of all the new stuff you have used.
mkh9
Are you on a prescription that might be causing this? Antibiotic did that to me. It was a allergic reaction, and had to call doctor that took me off the meds. If not then have you been outdoors in the weeds, because it could be poison ivy. If the plant has leafs in three leave it be.