What Causes Dry Patches Of Skin On The Outer Thighs?

I have circular dry skin patches. These patches are located on both my right and left outer thigh(about 5 or 6 on each side)..and the right side of my abdomen. I asked my doctor about it and attempted to show them to him...but he refused to look or touch the patches. he wrote them off as eczema due to my allergies and asthma. please I need to know what this is and how to fix it.