Cucumber may cause an oral allergy syndrome, which is an allergic reaction to plant proteins. Some persons who are allergic to pollen may be affected by this occurrence. Following the eating of the offending meal, itching and burning feelings arise in the mouth, lips, and throat. Symptoms might fade away in a matter of minutes. However, you should speak with your doctor, who may send you to an allergist to evaluate the origin of the response and any preventative precautions that may be taken.