Hello..Thanks for the query
You might be suffering from either a Contact dermatitis
due to the diaper or Candidal intertrigo in your groin area.
You may apply a topical steroid
for 3-5 days in the area and have an oral anti allergic tablet like Allergra to reduce the itching.If this does not show any improvement, i suggest you visit a dermatologist
and get an examination done.
Contact dermatitis may occur due to components in the adult diaper
, as well as to the excretory contents that it traps.You will need to determine what exactly is a cause and take steps to avoid it accordingly.
Hope this is helpful,