Currently there is no clearly effective way to prevent eczema. Many studies have tested a variety of eczema prevention strategies in pregnant and breastfeeding women and in infants. These include emollients or moisturizers, probiotics, prebiotics, synbiotics, vitamin D supplementation, hydrolyzed baby formula, early introduction of egg or cow’s milk, dietary supplements during breastfeeding, dust mite avoidance, Bacillus Calmette-Guerin (BCG) vaccination, antimicrobials, anti-worm medications, and antibiotic avoidance. Of all these experimental interventions, only a few have led to a small or modest reduction in the risk for childhood eczema.