Here is my story of how I noticed and diagnosed a latex allergy:
I wore latex medical gloves multiple times a day when changing diapers when I was a teacher. I probably wore these gloves for nearly a year before I started to have problems.
I think the first problem came about during the winter months and my hands were dry and cracking from hand washing 60+ times a day and the cold weather. With my skin already in a compromised state, I began having red skin discoloration on my entire hand up to where the glove stopped. Since it was possible to have latex free gloves, I tried using those for a while. My hands were still red many days, but my skin hurt less.
My next known exposure was when I touched rubber cement. I was gluing many pieces of paper one afternoon. If you have ever used rubber cement in excess you know it ends up on your hands and you use your fingers to remove globs or strings of the glue. I washed my hands when I was finished, but I still exposed my skin to it. Later that night both of my hands got red in exactly the shape of a latex glove I used to wear. I guess for me my body recognized the latex and reacted in all the places it had contacted in the past.
The last latex exposure I had was the worst of them all. In a hurry, and great need, I put on a latex glove to help a fellow teacher with a very ill child that needed cleaned up immediately. I knew it was latex when I put it on, so my part in helping was to quickly remove the child's soiled clothing then take the gloves off. I probably only had them on for three minutes tops. A few days later I ended up needing to got the doctor's office. I received a steroidal cream to use topically on my hands, and it was recommended I get a prescription for an epi-pen. I am fortunate, I have never had any breathing symptoms from my allergy.
For many, like me, a latex allergy can be progressive over time. As your body recognizes it and knows it does not want contact, it will react in increasingly strong reactions. I went from exposure multiple times a day to getting inflamed skin with contact lasting only 3 minutes or less and thorough hand washing.
So, since many people can tell their skin is sensitive but do not necessarily go to the doctor here are some products I have researched to avoid OR have had personal experience with and have learned to avoid.
*Industrial Adhesive-look closely it likely has latex
Paint-most wall paint has latex, I am not sensitive to this however-but some might be
Resistance Bands-some of them
Bands used during blood draws
Duct Tape or other high adhesive tape
Envelope Glue (don't lick it, use a sponge!)
Feminine Pads-just note that some adhesives on the back side might contain latex. If you are very active and often have bunching or your pad starts to un-stick from your underwear, you might have adhesive near or on your skin.
There are many other possible items with latex, so you should research further if you have, or think you have, a latex allergy. I hope this information at least helps in your initial research and what to avoid!