Apples and pears are members of the same general family of fruits. People who are allergic to one of the two fruits often are allergic to the other. Oral sensitivity to the fruit of an apple or a pear tree is linked to a birch pollen allergy. Birch pollen causes a cross-reactivity with apple and pear fruits.
Birch Pollen Allergy
Birch pollen is one of the many types of tree pollen that causes hay fever symptoms, according to WrongDiagnosis.com. Each spring, summer and fall trees release pollen into the air. Tree pollen allergies can cause itchy eyes, watery eyes, sneezing, coughing and headaches.
Connection to Fruit
In addition to causing general hay fever symptoms, birch pollen allergy is linked to an allergy to pear and apple fruits. According to the website Informall, people with a birch pollen allergy may develop an allergy to apples because of a similar protein. A protein in birch pollen, thought to cause allergy symptoms, is similar to apple proteins. Apples and pears are members of the same fruit family. As a result, the fruits share similar proteins. Most people who are allergic to apples are also allergic to pears.
Oral Allergy Syndrome
Pear and apple allergies are known to cause a condition known as oral allergy syndrome, according to the Calgary Allergy Network's website. Oral allergy syndrome is an allergy to certain types of raw fruits, vegetables, seeds, spices and nuts. People are not always allergic to all types of fruits known to cause oral allergy symptoms. However, people are generally allergic to the groups of fruits, vegetables or nuts that belong to a family.
The Calgary Allergy Network's website states that symptoms of an oral allergy syndrome to apples and pears can range from mild to severe. Mild symptoms include an itchy, tingly mouth while eating the raw fruit. Moderate symptoms include swelling of the lips and tongue, itchy eyes, runny nose, sneezing and rash where fruit was handled. Severe oral allergy symptoms may be life threatening. A person with a severe oral allergy to apples and pears may vomit, have trouble breathing, wheeze, and experience throat swelling and anaphylactic shock.
Treatment for an oral allergy symptom varies depending on the severity of the allergy. In most cases, apple and pear allergies occur only while eating or handling the raw fruits. Sometimes cooking the fruits will resolve allergy symptoms. Other people may avoid symptoms by obtaining allergy shots. In most cases, it is best for a person with an apple or pear allergy to avoid contact or consumption with apples and pears.