Hello,
How old is your baby?
When the erythema presents as a dark, glowing redness, it is very possible that there is a fungal superinfection. Have you tried creams so far?
I suggest applying clotrimazole 1% cream (Canesten) twice a day to the entire rash and a few centimeters around it for one to two weeks (or until a few days after the rash disappears)
You could also combine with a 1% hydrocortisone cream in a thin layer twice a day to decrease the inflammation.
During diaper changes, apply a 40% fragrance-free zinc cream. There is no need to completely remove the remaining zinc cream before reapplying it.
Whenever possible, leave the child's buttocks in the air as moisture will aggravate the infection.
Limit bathing as much as possible and dry the buttocks afterwards as soon as possible by patting rather than rubbing.
For pain, Tylenol could be given for the first few days while the treatment works. By providing me with your child's weight and age I can help you calculate the appropriate dose.
I assume that the child has no allergies or special health conditions. If the situation seems to get worse within 48-72 hours, if the child is inconsolable, has a fever or refuses to eat, consult a doctor. If these options do not improve the situation within a week, consulting a doctor is also a safer option to assess the severity of the possible superinfection.
Hopefully this information will be helpful to you!
Mélodie