3 month old and her armpit..HELP

BreeAnna

So I noticed last week that DD has a red area in her armpit. I bathe her daily. Wash and pat dry... I apply powder to her armpits and area where diaper sits. Then I noticed this... the whitish area if from baby powder. Should I make her an appt? What could it be? I raised her arm to apply the powder and noticed that it cracked open and slightly bled. I dont want an infection happening. I'm trying not to freak out