Itchy, Inflamed, and Red Bumps?

Michelle
me and my sister were outside by our pool for about an hour yesterday just lying on the ground tanning and today we both have the exact same red, itchy, inflamed, bumps on our nipples (one on each nipple). we read that it could be from our swimsuits rubbing against our breasts but I'm not sure, please help? do any of you know what it is? have any of you had this before?