When writing, we often seek synonyms to diversify our word choice and avoid repetition. For the phrase "break out with," some similar alternatives include "erupt with," "develop into," "suddenly exhibit," and "manifest with." These phrases are particularly useful when discussing sudden occurrences of a physical or emotional nature. For example, instead of writing "he broke out with a rash," one could use "his skin suddenly erupted with a rash." Using varied synonyms can add depth, intrigue, and dynamism to writing, leading to a more engaging read for the audience.