The signs of an allergic reaction to pineapple range from an itchy rash or watery eyes to a deadly condition called anaphylaxis. An allergic reaction can cause the entire body to go into shock, which can lead to death. Pineapple reactions are often mistaken for other conditions such as asthma, stomach or intestinal problems, or eczema. Like all allergic reactions, a reaction to eating pineapple occurs because the immune system mistakenly reacts as if a harmful substance has entered the body. A reaction can occur as soon as someone eats the fruit, or it can take place up to five days after consuming it.
People often do not realize that it is pineapple they are allergic to. Upon eating it, someone might get cramps in the lower abdomen. The problem could be mistaken for a stomach virus but can be severe enough that physicians mistake it for other conditions. Constipation can also occur as an allergic reaction to pineapple, or diarrhea might result and be bad enough to cause dehydration. Some people experience swelling in their throat when they eat the fruit, which can make it hard to breath and requires emergency medical care.
Respiratory symptoms are sometimes misdiagnosed as asthma or other serious conditions of the lungs, and often persist over long periods of time before the pineapple allergy is discovered. Less severe symptoms of an allergic reaction to pineapple include watery, itchy, or red eyes; hives on the skin, facial swelling, and tingling in the mouth. Low blood pressure is a symptom in some people which can cause lightheadedness and dizziness. If an anaphylactic reaction occurs, then a person can have so much swelling in the face and throat they can suffocate. Fatal cardiovascular and gastrointestinal effects can also occur with this severe of a reaction.
It is important to be tested for allergies if any reaction is suspected. Anyone who is allergic to nuts and fruit should be aware of the possibility of an allergic reaction to pineapple if they eat it. A severe anaphylactic reaction can be treated with adrenaline, and asthmatic symptoms can be dealt with by taking bronchodilators or other medications used to treat asthma. Antihistamines are also used because the immune system produces histamines in response to the allergy. Mild effects may not have to be treated, but to avoid more serious reactions, a person with a pineapple allergy should avoid the fruit altogether, as reactions can increase in severity with continued exposure.