There are many possibilities. Essentially (1) rule out allergic reaction (2) rule out insect bites (3) rule out diabetes (sometimes causes skin eruptions) (4) rule out hemangiomas, which are common in the over sixty set, and harmless. As Jen12977 stated Benadryl would be a reasonable treatment, as well as low-dose cortisone cream (available at a drugstore) rubbed on the skin.
Red bumps are caused by a number of different things a little more info would be helpful. I will start by saing if the area is itchy take Benadryl if you have the Benadryl cream that may be better to use. It could be that you came into contact with something you are mildly allergic to it could be the soap used, laundry detergent, dry skin, bug bites, etc.