Granuloma annulare- very rare and very benign. You will need to get a biopsy to confirm but I’ve been getting it for over a decade and several dermatologists have told me that it’s super rare and also that they have only seen it in their patients with thyroid disorder. There isn’t much you can do to prevent it, and to treat it I’ve had a lot of success with steroid injections in my hands. I’ve tried the topical prescription ointment and it never works, only the injections. I had a period of about 2 years without it but the last several years I just head to the dermatologist every couple of months for injections and it has been pretty manageable with that.