Aw, I'd definitely bring this up with your pedia, mama, white patches after a rash can be a few different things, at meron ring possibility na post-inflammatory hypopigmentation lang, pero mas safe na ma-check ng doctor kasi kailangan niya makita talaga. One of my mum friends' baby had similar after eczema flare-up, and doc assured her it would fade, pero importante pa rin na ma-assess ng professional para sa peace of mind mo!