Without examination, confirmation of a diagnosis is tough but it can be contact dermatitis, friction rub with clothes, hive
s, dermatitis (atopic, contact, allergic), heat <span style = 'background-color: #dae8f4'>rash</span>
or excessive sweating causing sweat dermatitis.
You may try calamine lotion on the rash
. You should also maintain hygiene and try to keep the area clean and dry, wear loose-fitting cotton clothing. Take some antihistaminic like Benadryl (causes drowsiness) or Claritin to relieve itching.