The most common olive allergy is caused by pollen that is released by olive trees. Olive pollen release occurs during the spring and can result in mild to serious respiratory symptoms. Olive trees are evergreen trees that are native to the Mediterranean, Asia and Africa, though they have been introduced into many other countries. People are susceptible to olive pollen allergies anywhere olive trees grow.
Olives and olive oil may also cause allergic reactions that manifest in the form of dermatological or gastrointestinal symptoms.
The olive tree has been recognized as a major cause of seasonal respiratory allergies in Mediterranean countries, according to an article by Prof. Gennaro D'Amato's published in September 2007 by The UCB Institute of Allergy.
People who are allergic to olive tree pollen can suffer from rhinoconjunctivitis. Allergic rhinitis, also known as hay fever, is an allergic reaction that occurs when the immune system overreacts to inhaled substances, such as pollen. Symptoms include a runny nose, sneezing, coughing and wheezing.
Allergic conjunctivitis, another reaction to olive pollen, causes symptoms such as runny, watery, itchy red eyes and inflammation of the eyelid's inner membranes.
The olive pollination season usually lasts from the beginning of May until the end of June. Some patients who are allergic to olive pollen are symptomatic only during pollination season, but others have clinical symptoms throughout the year, according to research by Celal Bayar University's Department of Internal Medicine.
In California, the state that grows most of the olives in the United States, olive trees produce such highly allergenic pollen that some people have difficulty even driving by olive orchards. The Allergy, Asthma and Immunology Foundation of Northern California explains that olives begin pollinating later in spring than other trees and grasses, and because they are heavy pollinators, they can trigger serious asthma.
Contact allergies to olive oil are rare, but a study of massage therapists conducted by Drs. Marlene Isaksson and Magnus Bruze from the Department of Occupational and Environmental Dermatology at Malmo University Hospital in Sweden, demonstrated that some people can develop sensitization and allergies to olive oil. This contact allergy can cause hand eczema, an especially problematic condition for massage therapists and other people who handle olive oil.
Based on this research, the Department of Occupational and Environmental Dermatology advised massage therapists to avoid using olive oil as part of their treatments if they or their patients have had a history of any type of eczema.
Olive Allergy Prevention
To prevent olive allergy flare-ups, some people stay indoors when the pollen count is high. It may also be helpful to use HEPA filters when vacuuming, changing clothes, showering and washing hair that has come into contact with the olive tree pollen.
Olive Allergy Treatment
Antihistamines and nasal steroids can be used to relieve the symptoms of an olive tree pollen allergy. Decongestants or nasal irrigation with a neti pot can clear nasal congestion. Some people benefit from immunotherapy or allergy shots, which involve giving injections of a small amount of the pollen allergen over a period of time. In some cases, the immune system becomes desensitized and the effects of the allergy may lessen.