Thanks for the query.
You have developed an allergic reaction
Like any other drug even premarin can cause reactions.
Please apply a mild steroid
This will control the inflammation.
Try to stop the drug and see response.
sometimes a change in brand also is helpful.
Please meet a dermatologist
if it persists.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.