I received these nice pictures and a question via email the other day. The mother was concerned as she had found this "spot" on her 6 year old son's back. He was otherwise well and she did not see any other "spots" or rash.
Her son complained that the "spot" was itchy so being the good mother she applied some over the counter cortisone cream for several days (which I always tell patients to try). After 2 days of it not improving, but not worsening, she thought it might be ringworm (also a good thought) and she applied an OTC anti-fungal cream. Again, the rash was not better, but really not worsening or spreading. That is an important part of the history.
Now in medicine you learn about red herrings, which are part of a patient's history that may not really have any bearing to their current problem....but one has to consider it. In this case, her dog developed a lesion and was taken to the vet and was diagnosed with a staph infection, but the vet told the mom that the dog was not contagious to humans. Red herring or is that the problem?
After looking at all of the pictures (which is never as good as seeing a rash in person), I am thinking that this may be nummular eczema, (nummular means coin shaped, hence the round) The history is right as is was not bothersome other than being itchy, and eczema is often called the "itch that scratches".
With all of this cold dry weather and heaters on full blast all over the country eczema is having a heyday. I have seen a ton of these little inflamed patches on skin of all ages (my own hands are a mess). The treatment of choice is to moisturize the skin and also the use of a topical steroid. But, it takes a long time to see an improvement in the spots and they may change on a daily basis depending on the weather, bathing and how much lubrication and moisturizing you are doing.
I would use an OTC moisturizer that contains ceramides (Cetaphil Restoraderm, Cerave, Aveeno for eczema) and use it liberally and frequently. I would also apply an OTC steroid several times a day (under the moisturizer). Eczema also sometimes requires a stronger topical steroid that is prescription.
Hope that helps.....but if not improving after 7-10 days it may be worth a visit to your pedi for up close and personal diagnosis.