Hi, I Have Molluscum Contagiosum On My Genital Area, I

Hi, I have molluscum contagiosum on my genital area, I consulted a dermatologist and he used liquid nitrogen, it's been a week, I see physical change in them but they are not gone yet and new ones are appearing but I was prescribed a lotion to apply on them as soon as I suspect them. Why is it reoccurring? Is it from the underwear?