I have these circle like paches-rashes that apear near my right elbow from time to time. Doc wrote it of as "stress" without any tests. Problem?

Erythema multiforme? This may be localized erythema multiforme secondary to recurrent herpes infection. A skin biopsy and blood test can confirm diagnosis. Treatment with oral antivirals could treat and prevent rash.
Possibly. You might have ringworm; it's impossible to diagnose a skin disorder without seeing it. Consider seeing a dermatologist, or another primary care doc. Try to be as specific as possible about when/where the rashes start. Take pictures if they'll disappear before your doctor sees them! "google" them by describing them just like you did, and hit "images". Bring the info to your doc and ask.