come out in something        
phrasal verb with come verb uk/kʌm/ us/kʌm/ came | come
 UK(皮肤上)出现(斑点等) 
If you come out in something, such as spots, they appear on your skin.
  This heat has made me come out in an itchy red rash. 热得我出了一片又红又痒的痱子。