From the description it seems you are having lichen simplex chronicus
. The underlying cause in your case could be fungal infection
, eczema ,intertrigo
or stress and anxiety.To treat the same, you may use a combination of steroid, antibacterial and antifungal cream for a week. To treat the itch also use an antiallergic like cetirizine
. Keep the area clean and dry as much as possible.
Hope that answers your query. Take care.