Identifying pear allergies can take some detective work, because pears produce relatively few allergic reactions. In fact, allergists often place this rarely allergenic tree fruit on the menus of control diets to help patients identify other allergies. People who experience adverse effects after eating pears may mistakenly blame food poisoning, which shares many allergy symptoms. Sensitivities to apples and quinces may further confound a patient's diagnosis, whereas an allergy doctor will realize that trouble with these related fruits may point to a pear allergy.
Tingling, itching or tenderness may constitute the first signs of pear allergies. Itching may begin in the mouth, lips and throat, or in the fingers after handling pears. As the National Institutes of Health (NIH) relates, once allergens are ingested, food allergy symptoms develop along the digestive tract. Itching can start on contact and progress as allergens travel through the bloodstream and digestive organs. The mucous membranes are particularly susceptible to itching, which may spread to the eyes and other areas.
Inflammation usually follows an allergic reaction immediately or within an hour or so. The Mayo Clinic identifies the lips, tongue, face and throat as sites that may experience obvious swelling due to pear allergies. Severe inflammation can make it difficult to see or to breathe.
The skin is served by many blood vessels that carry allergenic proteins along with nutrients and waste. As the effects from pear allergies spread to the skin, eczema allergy symptoms follow. According to the NIH, a patient's skin may form red, scaly rashes, or painful hives in which the inflamed skin develops raised welts. Because many types of allergic reactions produce contact rashes, these symptoms can only be associated with pears if the fruits were recently ingested.
An allergy to pears will eventually affect the digestive system. The University of Maryland Medical Center notes that this may take two hours or more, perhaps first appearing as abdominal pain. Stomach cramps and vomiting may be strong and come on suddenly. Patients may also experience diarrhea. These allergy symptoms are similar to those of food poisoning, but when combined with other signs, may indicate a patient's problem with pears and related fruit.
Anaphylaxis marks the most rare and severe allergic reaction to a food, and it requires emergency treatment. Combined digestive and respiratory trouble along with a drop in blood pressure create a systemic imbalance that threatens the body's overall metabolism. The Mayo Clinic reports that signs of anaphylaxis include dizziness, shortness of breath, uneven pulse and loss of consciousness.