Yogurt is a complicated food in the context of eczema because it can act as both a trigger and, for some, a beneficial food. On the trigger side, it contains the same milk proteins (casein and whey) as regular milk that can cause immune reactions and skin inflammation. It also contains some histamine produced during fermentation. On the potentially helpful side, the beneficial bacteria in yogurt can support gut health, and the fermentation process partially breaks down some of the allergenic whey proteins.

This is why some dairy-sensitive people find they can tolerate yogurt even when regular milk causes problems. In clinical milk ladder protocols, yogurt is introduced after baked dairy because it represents a middle ground — partially broken-down proteins but still unheated. About 46% of milk-allergic children can tolerate fermented dairy products.