However a circular lesion on the breast with a red ring around it can be nummular eczema, tinea infection (fungal), pressure urticaria due to
jewellery or buttons, or insect bite. Skin lesion of ring worm too looks like this but usually there are more than one. It can also be due to SLE. If the lesion does not itch or has pain, it could be a herald patch of pityriasis rosea. Pityriasis rosea is an acute, benign, self-limiting skin rash.