armpit rash

Hey ladies & this post is a super TMI.. but have any of you ladies ever had a rash under your armpits? it is itchy, it resembles an ingrown hair but I don’t think it is. nothing has changed in my care such as deodorant or detergent I am just wondering if any of you ladies have ever experienced this & what you did.. I went to my doctor and she prescribed a steroid cream which I have yet to use because I am almost 5 months PP breast feeding. any insight, advice, etc. Thank you xoxo🤍