I am experiencing. my left axillary is quite itchy on a regular basis with no signs of rash or swelling, what could it be?

Multiple possibility: the hairy area armpit usually itch when its wet and sweaty , you can try to remove the hair and see , but definitely not shaving because with hair growth after shaving it can be so itchy , but you need to make sure no change in color (mild rash) to role out fungus infection, also it can be 2/2 antiperspirant deodorant try to change it to mild non -fragrant one good luck