Meaning of “come out in sth” - Learner’s Dictionary

come out in sth

phrasal verb with come uk us /kʌm/ verb (past tense came, past participle come)

If you come out in a skin disease, it appears on your skin:

When I eat cheese, I come out in a rash.

(Definition of “come out in sth” from the Cambridge Learner’s Dictionary © Cambridge University Press)