Fruit allergies are common, and the relationship between peach and nectarine allergies can be confusing. While similar, individuals can react differently to each. Understanding their allergenic distinctions helps clarify why some experience symptoms from one but not the other.
The Close Relationship Between Peaches and Nectarines
Peaches and nectarines share a close botanical connection, both belonging to the Prunus persica species within the Rosaceae family. Nectarines are a variety of peach, distinguished by a single gene that results in their smooth, fuzz-free skin, unlike the fuzzy skin of peaches. Despite this superficial difference, they share common proteins.
Their shared genetic background means peaches and nectarines contain similar protein structures, including allergens. The Rosaceae family also includes other stone fruits like plums, cherries, apricots, and almonds, which can contain related allergenic proteins. Therefore, an individual allergic to peaches or nectarines might also show sensitivities to these related fruits due to shared proteins.
How Allergic Reactions Can Differ
Allergic reactions to peaches and nectarines can vary due to differences in specific types and amounts of allergenic proteins. This is known as cross-reactivity, where the immune system recognizes similar proteins in different substances. Some react to Lipid Transfer Proteins (LTPs), such as Pru p 3. These are concentrated in the fruit’s skin and are heat-stable, causing reactions even in cooked or processed forms. Pru p 3 is considered a major peach allergen, and sensitization to it is common in Mediterranean regions.
Another common reaction involves profilins or PR-10 proteins, like Pru p 1, often associated with Oral Allergy Syndrome (OAS). OAS causes mild symptoms like itching or tingling in the mouth, lips, or throat, usually appearing within minutes of eating raw fruit. Unlike LTPs, these allergens are heat-sensitive, so individuals with OAS may tolerate peeled or cooked peaches and nectarines. The presence and concentration of these proteins can differ slightly between peaches and nectarines, or even within different varieties, leading to varied immune responses.
What to Do If You Suspect an Allergy
If you suspect an allergy to peaches, nectarines, or related fruits, seeking professional medical advice from an allergist is a prudent next step for an accurate diagnosis. Allergists can conduct diagnostic methods like skin prick tests (applying fruit extract to skin to observe reaction) or blood tests (measuring specific IgE antibodies). A “prick-prick” test using fresh fruit is highly effective for peach allergy diagnosis.
Until a diagnosis is confirmed, it is advisable to avoid the suspected trigger fruit and any other fruits that cause similar reactions. For mild symptoms, over-the-counter antihistamines can help manage discomfort, but these may not be effective for rapidly occurring OAS symptoms. For severe reactions like anaphylaxis (difficulty breathing, drop in blood pressure, or loss of consciousness), immediate medical attention is necessary. An epinephrine auto-injector may be prescribed for emergency use.