Other skin conditions that result in dry, thickened skin on the foot include athlete's foot (tinea pedis), leg vein problems (venous stasis), psoriasis, and skin rashes caused by allergy or irritants. A common cause of dry, scaly skin and accentuated skin lines on a child's feet is the condition atopic dermatitis. 1  Photos and descriptions of eczema, atopic dermatitis, contact dermatitis, and athlete's foot.  Physical Stress: The environment inside a shoe can get very hot -- sometimes well over 120 degrees.