Hm, that's strange. That it is just one leg. if it were clothing, you'd think it would be both. Do you have any other itchy patches anywhere else? Eczema? What about a little fungal issue there? Fungus loves moist areas if you sweat that don't get a lot of air. ?? I had ON one foot a significant itch that went on for some time. Anyway, have you tried some of the athlete's foot powder on it just in case? Otherwise, see your doctor. Sorry I wasn't more helpful!