An allergy to nectarines is possible and is a relatively common form of food hypersensitivity. Nectarines are stone fruits, belonging to the Rosaceae family, which also includes peaches, plums, and cherries. Allergies to this group are frequently linked to specific plant pollens. This connection means that individuals who experience seasonal allergies may also react to the fruit’s proteins, as the immune system mistakenly identifies them as a threat.
Recognizing the Symptoms of a Nectarine Allergy
Reactions to consuming nectarines range from mild, localized irritation to severe, life-threatening systemic responses. The most frequent reaction involves mild symptoms localized to the mouth and throat, known as Oral Allergy Syndrome. This can involve immediate itching, tingling, or burning sensations on the lips, tongue, and throat shortly after eating the fresh fruit. Swelling of the lips, mouth, or tongue may also occur, but these reactions are typically short-lived and resolve once the fruit is swallowed or removed.
Some individuals may experience symptoms that extend beyond the oral cavity. Skin reactions like hives, which are raised, itchy, red patches, may develop on the body.
More concerning are systemic reactions that involve multiple organ systems. Gastrointestinal distress can manifest as nausea, vomiting, or abdominal pain. Respiratory symptoms, such as coughing, wheezing, or difficulty breathing, indicate a more serious reaction. The most severe reaction is anaphylaxis, which involves a rapid onset of symptoms including a drop in blood pressure, dizziness, swelling of the airways, and loss of consciousness, requiring immediate emergency intervention.
Understanding Cross-Reactivity and Oral Allergy Syndrome
The explanation for why nectarine allergies occur so frequently is rooted in cross-reactivity, which forms the basis of Oral Allergy Syndrome (OAS), also known as Pollen-Food Allergy Syndrome (PFAS). Cross-reactivity occurs when the immune system mistakenly recognizes the proteins in certain foods as structurally similar to proteins found in common pollens.
The main culprit in nectarine-related OAS is the allergy to birch tree pollen, which is common in the Northern Hemisphere. A person allergic to birch pollen has produced Immunoglobulin E (IgE) antibodies to the major birch allergen, Bet v 1. Nectarines and other stone fruits contain a similar protein, Pru p 1, which belongs to the Pathogenesis-Related protein family 10 (PR-10).
Because the Pru p 1 protein is structurally similar to the Bet v 1 protein, pre-existing IgE antibodies react to the fruit protein. This cross-reaction causes the mild, localized allergic symptoms characteristic of OAS. The allergenic proteins are easily broken down by heat or digestion, which explains why many individuals can safely consume cooked nectarines. The cooking process denatures the PR-10 protein, rendering it unrecognizable by the immune system.
Diagnosis and Practical Management
Confirming a nectarine allergy requires consultation with an allergist. The diagnostic process begins with a thorough review of the patient’s medical history and the nature of the symptoms experienced. Diagnostic tools are then used to confirm the presence of IgE antibodies that react to the fruit proteins.
A common method is the skin prick test, where a small amount of the allergen extract is introduced beneath the skin’s surface. A positive result, indicated by a raised, red welt, suggests sensitization to the substance. Blood tests can also be performed to measure the level of specific IgE antibodies circulating in the bloodstream.
The primary strategy for managing a confirmed nectarine allergy is strict avoidance of the fresh fruit. Individuals must remain vigilant about cross-contamination, particularly in food preparation settings. Since OAS is common, affected individuals should also be aware of other cross-reactive foods, like apples, pears, and cherries, and monitor their reactions.
For managing mild symptoms like oral itching, over-the-counter antihistamines may be recommended. However, for individuals who have experienced systemic reactions or are at risk for anaphylaxis, emergency preparedness is paramount. This includes carrying an epinephrine auto-injector (EpiPen) and understanding how to use it immediately in the event of a severe allergic reaction.