If you know what clothing causes your rash, and you stop wearing it, the rash usually goes away by itself, and you don’t need medications.
But if the condition is serious, the doctor may treat you with antihistamines, moisture creams, or steroids to give you some relief while your rash goes away. Try an oatmeal bath to soothe your skin. More severe cases of dermatitis may be treated with oral steroids like prednisone and wet dressings.