I have a raised, red, itchy line on the back of my left leg, exactly
where my biking short elastic was.  It has been present for 5 days and
has not decreased in size, redness, or itchyness.  I recently found
another line on my left ankle and it looks like another one starting
to the inside of my knee.  What could this be and how do I treat it?

Probably irritant contact dermatitis. Treat with topical steroids,
maybe benadryl (or zyrtec is better for non-drowsy). If it's small
bugs that are still in the skin though, you may need something else.

I would personally suggest seeing a doctor if you have a persistant
medical issue and you can't identify it. Try a dermatoligist.

Nenna-GA
Google Answers Researcher