reoccuring pityriasis rosea

My doctor diagnosed Pityriasis Rosea 7 months ago , but it is reocuuring once i stop medication. Doctor also did biopsy to make sure the diagnosis.  initially derm diagnosed pityriasis rosea, I had all symptoms, I had herald patch, he gave ointment and it worked too.... but now its coming back without Herald patch, on thighs, little on hands, little on stomach. my doctor never gave oral medicine and he never gave any shots,he gave oitment only and it worked, but condition is coming back when i stop medicine.

just for more info,I am married from last 5 years and my husband has not got any infections from last 7 months....He is healthy so it looks like its not STD. He is the only partner i has sex with. I am 27 years old female.