In reference to food, ânitrateâ really means sodium nitrate, but should really refer to sodium nitrite. While these are two completely different chemical compounds, they are often used interchangeably by those outside of the science realm. 1  Sodium nitrate is a type of salt, naturally found in Chile and Peru.
Symptoms. Diagnosis and Treatment. Prevention. 1  Patches of chronically itchy, dry, thickened skin, usually on the hands, neck, face, and legs (but it can occur anywhere). 2  In children, the inner creases of the knees and elbows are often involved.
1 The causes of eczema -- including atopic dermatitis -- are unknown. 2  Eczema is chronic, marked by periods of flare-ups. 3  Although the itchy, red rash associated with atopic dermatitis can appear anywhere on the body, it is often found on the elbows, knees and face [source: National Eczema Association ].