Good evening We have an allergy to diapers. (I think so) We tried three…

Good evening We have an allergy to diapers. (I think so) We tried three types of diapers and here it doesn't go away (photo below). We smear with Sudocrem, plain zinc ointment, we smeared a lot and it doesn't go away. And what's interesting is that only on this spot it goes away, and then pops up again. What kind of diapers would you recommend? Or ointments?