Thanks for your query
The lesions you mention might be due to fungal infection
.It is called Tinea Corporis
This has a tendency to spread in the form go an oval ring with a clearing in the centre.Topical anti fungals can be applied for about 2-3 weeks to cure this.
However, since there are possibilities that it might be other similar looking dermatological disorders, you should visit a dermatologist
before starting medications.The presence of fungus in doubtful cases can be confirmed by an examination of the skin scraping and culture.
Hope this is helpful