from the description provided it could either be eczema
or it could be an yeast or candidal infection. Ring eczema is a term used when eczema occurs beneath a ring. This occurs due to metallic component of ring itself or due to trapped water , soap beneath the ring. Candidal infection too can present as wet itchy lesions with pustules.
It would be better to get the diagnosis confirmed and start s specific Treatment. You may try using combination of mild steroid
, antifungal and antibacterial cream over the lesion to help it heal. Avoid using harsh soaps. Take oral antihistamine to alleviate the itch.
Hope that helped.