What Causes Legs, Abdomen And Ribcage Itching With Bruising?

I am 25, exercise at least 3times a week, have had no major diet/vitamin/lotion, ect change in the past few months. No allergies. Have never been sick. Light smoker. I have had very itchy legs for the last 3 weeks. This week I have noticed a large bruise that has come and gone 3 times on my lateral left leg. Also I wake up in the morning scratching my lower abdomin and rib cage. The bruises are freaking me out. Whats wrong??