The various possibilities of rash/bites like lesions are varicose dermatitis (occurs over a varicose vein), discoid
eczema (this may be both the dry or wet type), asteatotic
eczema or a variant of discoid
eczema over dry skin, gravitational eczema, atopic dermatitis, contact dermatitis (if you work outdoors or somewhere where some chemical or plant or any thing else comes in contact with your legs), or even psoriasis and tinea corporis (a fungal infection). Do consult a skin specialist.