Thank you for your query.
Unfortunately , not having a family history of eczema or psoriasis
does not entirely exclude the possibility that you have those conditions. However those are not the only possibilities. Poor venous blood
return from the lower leg may also cause this, sometimes recognizable by the presence of varicose veins
. Also diabetes
may cause this, through damage to the small blood vessels. As you can see , the causes are many and wide ranging. Please get to a clinic for medical evaluation. I trust this helps you.