Allergen - Onion

Allergen Onion Test measures the level of onion-specific Immunoglobulin E (IgE) antibodies in the blood to determine whether a person has an allergic reaction to onions. Although onion allergy is relatively uncommon, it can cause symptoms ranging from mild itching and skin rashes to digestive discomfort or breathing difficulties in sensitive individuals. This test helps doctors identify whether onion is a possible allergy trigger and supports the evaluation of food-related allergic reactions as part of an overall allergy assessment.

Who Should Get This Test Done?

This test may be recommended if individuals:

●      Experience oral itching, lip swelling, throat tingling, or other allergy symptoms after eating raw or cooked onions.

●      Develop hives, itching, skin redness, or other skin reactions following onion consumption.

●      Have nausea, abdominal pain, or recurrent gastrointestinal symptoms that consistently occur after eating onions.

●      Have experienced a severe allergic reaction or anaphylaxis after consuming onions or foods containing onions.

●      Have a known allergy to other Allium vegetables (such as garlic, leek, or chives), work in environments with frequent onion exposure, or are being evaluated for multiple food allergies where onion is a suspected trigger.

Why Consider This Test?

Onion allergy can be difficult to identify because its symptoms may resemble the common irritant effects associated with handling or cutting onions. This test provides objective evidence of allergen sensitivity and helps differentiate true allergy from intolerance or non-allergic reactions.

A positive result supports the diagnosis of onion allergy and can guide dietary modifications, while a negative result may suggest alternative causes of symptoms. The test may also be useful in assessing cross-reactive allergies, including certain lipid transfer protein (LTP) allergy syndromes, where onion sensitivity can form part of a broader allergy profile. Given the widespread use of onion in home cooking and processed foods, accurate diagnosis is important for symptom control and patient safety.

More Information

Onions contain proteins that may trigger an immune response in some individuals, causing the body to produce allergen-specific IgE antibodies. The Allergen – Onion, Serum test helps determine whether these antibodies are present, making it easier to identify onion as a potential cause of allergic reactions. It is commonly recommended when allergy symptoms appear after consuming onions or foods containing them. The findings are evaluated along with clinical history and other allergy investigations to provide a complete understanding of the individual’s allergy profile.

Other Names

●      Onion Specific IgE Test

●      Allium Cepa IgE Test

●      Food Allergen Test – Onion

●      Onion Food Allergy Test

●      Specific IgE – Onion

●      Onion Allergy Blood Test