Twice in the last month after being outside doing a lot of walking, the lower inside part of my legs (ankle area) have red/blotchy marks and itch.  It goes away after 3 to 5 days.  Although it seems logical to attribute it to the walking and exposure to the sun, I have never had this response to activity and sun exposure before.
Hi Dear, Welcome to Chat Doctor. Understanding your concern. As per your query you have symptoms of red blotchy marks on ankle which could be due to contact with allergic and poisonous agent, bacterial infection of hair follicle, eczema, fungal infection, and poor hygiene. It could be due to skin photosensitivity due to sun exposure as well. Need not worry. I would suggest you to maintain hygiene and wear loose clothes as it will prevent skin eruptions. You should take anti-allergic medication such as Ben Chat Doctor.  You should apply topical antibacterial/ antifungal cream. Furthermore, you should visit dermatologist once and get it examined and start treatment after complete examination. Furthermore, you should take proper antibiotic course as well. Hope your concern has been resolved. Get Well Soon. Best Wishes,