Atopic dermatitis (AD), also called eczema, is a skin condition that causes itchy, dry, flaky patches. In the U.S., it affects about 10 million children and 16 million adults, many of whom develop it in middle age.

The only treatments are moisturizers to ease dryness, antihistamines to relieve the itch, and topical steroids to ease inflammation.

The cause is hard to pinpoint, but intriguing studies reveal that the standard American diet may be a major culprit.

Fast-food consumption has been associated with a 20% increased risk of adults developing AD and a 70% increase in the risk among adolescents. Interestingly, children born outside the U.S. have a 50% lower risk of developing AD, but their risk increases after living in the U.S. for 10 years.

Those facts led University of California researchers to investigate the relationship between salt intake and AD. (Fast food is loaded with salt.) They found that people with AD have higher levels of sodium in their diets and in their urine. And every gram of sodium consumed increases AD risk.

The good news? Consuming less sodium may control or even reverse eczema.

Foods that deliver more than half the added sodium in Americans' diets include:

• Breads and rolls

• Pizza, burritos, and tacos

• Soup

• Cold cuts, hot dogs, and cured meats

• Baked goods

• Chicken nuggets

Instead of eating those salt bombs, aim for a plant-based diet free of processed and fast foods. And substitute potassium salt (potassium chloride) for two-thirds of your table salt (sodium chloride).