Banana allergy symptoms usually develop right after eating the fruit. Physical effects may involve mouth and gastrointestinal disturbances or may escalate rapidly into life-threatening anaphylactic shock. According to the Nemours Foundation, children with banana allergies often outgrow them, whereas people who develop them as adults may have to avoid banana allergens for a lifetime.
The allergy symptom of itching in the mouth area may affect the lips, tongue and throat. Itching sensations may spread to the eyes and skin. In discussing these problems with their doctors, patients should disclose additional known allergies, which can aid in diagnosis. The Asthma and Allergy Foundation of America reports that many patients who get seasonal allergic reactions to ragweed or contact allergies to latex also have banana allergies. Mouth itching may be more intense during ragweed season, when patients' sensitivities are high.
The inflammation that causes itching usually brings swelling to the same areas of the body. Itching and swelling symptoms from bananas in ragweed hay fever patients may comprise the extent of their health problems. Symptoms limited to the mouth are called oral allergy syndrome. A greater reaction may raise welts on the skin, creating a red rash or hives. A severe allergic reaction to bananas can prompt the eyes and face to swell acutely, causing pain and tenderness and making it difficult for patients to see.
This inflammation may constrict the airways when swelling affects the throat, tongue and sinus areas under the eyes. The University of Maryland Medical Center relates that this condition may create difficulty in swallowing or breathing. These allergy symptoms can escalate to dangerous levels when combined with an adverse cardiovascular response.
Banana allergies become serious when the immune system mistakenly triggers a decrease in blood pressure. As respiratory problems restrict blood oxygen levels, anaphylaxis progresses toward shock, the Nemours Foundation reports. Serious allergy symptoms that require immediate paramedic assistance include a weak or racing pulse, light-headedness and sudden loss of consciousness.
Banana allergies cause a variety of gastrointestinal symptoms that often begin with nausea, notes the University of Maryland Medical Center. Stomach pain and cramping may take place shortly after eating bananas, as digestion begins. In some patients, however, allergic reactions to bananas provoke almost immediate vomiting or diarrhea.