Cucumber skin contains alkaloids, some people eat cucumber without peeling after consumption will stimulate the mucous membrane of the lips tingling symptoms, after half an hour or so the symptoms can disappear and do not need drug treatment. Some people have severe allergic reactions to alkaloids, after consumption, in addition to numbness of the lips will also appear red, swollen, itchy symptoms need to take oral antihistamines, such as paracetamol, cetirizine tablets and other drugs to treat and saline cold compresses. Before the symptoms of allergy subside, the diet should be light and pay attention to the cleanliness of the lips to avoid external stimulation. If you know that you are allergic to cucumber, first remove the skin and soak the cucumber in salt water for a while before eating or stir-fry the cucumber, because the alkaloids inside the cucumber will be destroyed after stir-frying so that the symptoms of allergy will be reduced or disappear.