A.S.
YOU HAVE AUTOIMMUNE PROGESTERONE DERMATITIS (APD).
I have this disorder and antihistimines DO NOT help. Prednisone was the only effective treatment until I had my ovaries removed (oophorectomy). You need to contact the allergy clinic at a medical school (UCSF) to administer a skin (intradermal) allergy test with progesterone. Good Luck!!