Diaper rash happens! Here are some tips on prevention and treatment:
On average, a diaper rash will noticeably improve within 2-3 days. If it persists (or you have any questions regarding diaper rash), contact your pediatrician.
For more information, visit this American Academy of Pediatrics link:
https://www.healthychildren.org/English/ages-stages/baby/diapers-clothing/Pages/Diaper-Rash.aspx