From the description it seems, you might have developed intertrigo
. Intertrigo is characterised by itchy burning red macerated rash. It can occur in obese
people or during humid climate when underclothes are too tight to cause friction in sweat prone areas like axilla
, groins, inner side of thighs or infra mammary area.
To treat the same
Keep the area dry and well ventilated. You may also dust the area with antifungal powder to prevent it from occuring
Wear loose cotton underclothes
Use a mild steroid
antifungal cream to treat the rash
Hope that solves your query. Take care.