 [ Symptoms ] how do i know if i am allergic to a medicationplavix  i am on generic plavix but have had a rash for several months that will not go away my internist thinks i am allergic to the plavix & is going to switch me to a different medication but i was recently diagnosed with lupus so am on plaquenil for that had the rash before started that med as long as i take steroids the rash does not itch but it does not go away i have tried all kinds of creams ointments etc if i switch medications & that is not the cause then what [ Disease ] i am sorry you are going through this medication management is challenging enough without throwing lupus into the mix your physician is in the best position to assess this situation if he or she feels the plavix is causing the rash then i would suggest listening to that advice using creams and ointments will not cause the rash to go away if it is in fact an allergic reaction to the plavix however creams and ointments might make the rash feel better if the rash is caused by an allergic reaction to the plavix then the only thing that will make the rash go away is removing the plavix which your internist already plans to do do not expect the rash to immediately disappear when your internist takes you off the plavix it may take some time for the rash to completely go away if the rash does not go away your internist will work with you to determine what is causing it and develop a treatment plan that reduces the side effects of any medication i wish you all the best as you go through this process could be an allergy to a pet dust or even a candle that you burn i would suggest seeing an allergist