To tell if you're allergic to Latex you would have to be exposed to Latex and then look for any signs and symptoms of a Latex Allergy.
Most cases of Latex Allergies occur after a few exposures to Latex and exposure to Latex can lead to skin rashes, hives, difficulty breathing, chest tightness etc.
Some gloves contain Latex as well as balloons.
The symptoms of a latex allergy are a skin rash on the area where you touched the Latex.
For example if you put on some Latex Gloves and are allergic to Latex then your whole top of your hand and sometimes the bottom of your hand and your wrist may have a rash.
Latex Allergies can also cause symptoms such as coughing, wheezing, scratchy throat, itchy and watery eyes, difficulty breathing and sneezing and runny nose.
Most cases of Latex Allergies are not very serious and usually go away on their own.
However in rare cases some people may be deathly allergic to Latex and can die if they don't get medical attention.
It would be a good idea to see a doctor if you do get symptoms of the latex allergy.
Disposable diapers used to contain Latex but some babies and toddlers were getting allergies to the Latex and so disposable diapers now no longer use Latex in the making of the disposable diapers anymore.