Arugula, also known as rocket, is a peppery, leafy green often enjoyed in salads, on pizzas, and as a flavorful garnish. Although rare compared to more prevalent food allergies, an IgE-mediated allergic reaction to arugula is medically possible and has been documented in clinical reports. This reaction is a true food allergy, involving the body’s immune system mistakenly identifying a protein in the arugula as a threat.
The Possibility of a True Arugula Allergy
A true allergy to arugula, or Eruca sativa, involves a specific immunological mechanism where the body’s immune system produces Immunoglobulin E (IgE) antibodies. When the person consumes arugula again, these antibodies trigger the release of chemicals like histamine, leading to allergic symptoms.
Arugula belongs to the Brassicaceae family, often called the mustard or cabbage family, which includes many common vegetables. The possibility of an allergic reaction is tied to this botanical classification, as shared proteins within this family can be responsible for sensitizing the immune system. For instance, a specific protein in raw arugula has been identified with a molecular weight of about 60–67 kDa that binds to IgE in sensitive individuals. This immune response is distinct from a simple food intolerance, which does not involve the production of IgE antibodies.
Recognizing Symptoms and Severity
The physical experience of an arugula allergy can range from mild, localized discomfort to a severe, systemic reaction. Mild symptoms often manifest within minutes of ingestion and can be localized to the mouth and throat. This may include a tingling or itching sensation in the mouth, lips, or tongue, a condition known as Oral Allergy Syndrome (OAS). Other less severe reactions involve skin symptoms like localized hives (urticaria) or minor digestive upset such as nausea or vomiting.
More severe reactions indicate a systemic response affecting multiple organ systems. These reactions may include difficulty breathing, wheezing, or a sensation of the throat swelling or tightening. A rapid drop in blood pressure, dizziness, or fainting can signal anaphylaxis, the most severe form of allergic reaction. Any sign of difficulty breathing, throat swelling, or lightheadedness requires immediate medical attention, as anaphylaxis can progress rapidly.
Cross-Reactivity and Non-Allergic Sensitivities
A reaction to arugula may be due to cross-reactivity with other botanically related items. Cross-reactivity occurs when the immune system mistakes similar proteins in two different substances for one another. Since arugula is a member of the Brassicaceae family, a person allergic to it may also show sensitivity to other family members, including mustard, cabbage, broccoli, or turnip.
An allergy to certain environmental pollens can also trigger a reaction to arugula, a phenomenon known as Pollen Food Allergy Syndrome (PFAS). For example, sensitization to mugwort pollen has been associated with cross-reactivity to foods in the Brassicaceae family. The allergenic proteins that cause this cross-reaction are often sensitive to heat, meaning a person might react to raw arugula but tolerate it when cooked.
Some adverse reactions to arugula are not true allergies but rather non-allergic sensitivities or intolerances to naturally occurring compounds. Arugula contains naturally occurring chemicals such as salicylates. In individuals with a salicylate sensitivity, consuming arugula can cause symptoms like headaches, asthma, hives, or gastrointestinal issues. Furthermore, the high fiber content of leafy greens can sometimes lead to general digestive upset, which is a mechanical issue, not an immune-mediated allergy.
Seeking Diagnosis and Managing Arugula Avoidance
If an allergic reaction to arugula is suspected, consulting a board-certified allergist for an accurate diagnosis is the recommended first step. The allergist can determine if the reaction is IgE-mediated or due to a non-allergic intolerance. Diagnostic tools often include a skin prick test using fresh, raw arugula (prick-by-prick testing) to check for an immediate IgE response. Specific IgE blood tests can also measure the level of antibodies in the bloodstream that are reactive to arugula proteins.
In some cases, a physician may recommend a supervised oral food challenge, which is the most definitive way to confirm a food allergy diagnosis. For those diagnosed with a true arugula allergy, the primary management technique is strict avoidance of the food. Practical avoidance involves careful reading of ingredient labels, as arugula may be listed under its common name “rocket” or simply as “mustard greens” in some blends. For individuals with a history of severe reactions, the allergist will prescribe an emergency action plan, including the use of an epinephrine auto-injector.