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Blood Test Tracker

Latex IgE

Measures IgE antibodies to natural rubber latex. A higher level means sensitization to latex, which doesn't always cause reactions.

AI-verified against cited sources. Awaiting expert reviewAlso called k82LOINC 6158-0

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What it is

Natural rubber latex is a milky fluid from the rubber tree. It is in many everyday items, such as gloves, balloons, rubber bands and some medical supplies. This test measures IgE antibodies in your blood that recognize latex proteins. Labs report the result in kU/L, often with a class from 0 to 6.

Why it matters

Repeated contact with latex can make some people allergic to it. Reactions range from itchy skin or a rash to a stuffy nose or asthma, and rarely to a severe reaction called anaphylaxis. A positive result means your body has made IgE to latex. It does not show how strongly you would react. People with a latex allergy may also react to some foods, such as banana, avocado, kiwi and chestnut, because they share similar proteins.

If it’s high

A higher level means your blood has IgE that recognizes latex proteins. This can go along with a latex allergy, but some people have these antibodies without ever reacting. Because the result can't show how severe a reaction would be, it is read together with your history of reactions to latex products.

Common causes

  • Latex allergy after repeated contact with latex, for example from gloves or medical devices
  • Sensitization without any reactions
  • Cross-reactive proteins in some plant foods, such as banana, avocado, kiwi and chestnut (called latex-fruit syndrome), and in ragweed pollen

What can help

  • If latex causes symptoms for you, ask your clinician about latex-free versions of gloves, bandages, balloons and other items
  • Tell your clinician, dentist and surgical team about a latex reaction or a positive test before any procedure
  • Ask whether tests for related foods or for single latex proteins would be useful

Usual ranges

What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.

For adults: 0–0.09 kU/L. Source: Labcorp, ARUP Laboratories, Quest Diagnostics, Thermo Fisher Scientific (Phadia), Journal of Allergy and Clinical Immunology.

ImmunoCAP class scale as printed by ARUP (the manufacturer's revised scale, per UR Medicine Labs 2022)

  • Class 0: absent or undetectablebelow 0.1 kU/L
  • Class 0/1: clinical relevance undetermined0.1 to under 0.35 kU/L
  • Class 1: low level0.35 to under 0.71 kU/L
  • Class 2: moderate level0.71 to under 3.51 kU/L
  • Class 3: high level3.51 to under 17.51 kU/L
  • Class 4: very high level17.51 to under 50.01 kU/L
  • Class 5: very high level50.01 to under 100.01 kU/L
  • Class 6: very high level100.01 and above kU/L

Labcorp class scale (ImmunoCAP, as printed on Labcorp sample reports dated 2016 to 2019)

  • Class 0: negativebelow 0.1 kU/L
  • Class 0/I: equivocal or low0.1 to under 0.32 kU/L
  • Class I: low0.32 to under 0.56 kU/L
  • Class II: moderate0.56 to under 1.41 kU/L
  • Class III: high1.41 to under 3.91 kU/L
  • Class IV: very high3.91 to under 19.01 kU/L
  • Class V: very high19.01 to under 100.01 kU/L
  • Class VI: very high100.01 and above kU/L

What can affect your result

  • How often you are in contact with latex, for example through work or medical care
  • Cross-reactivity with certain plant foods and ragweed pollen
  • Lab and method: class cutoffs differ slightly between labs
  • Results from different labs and assay systems can differ, so compare results from the same lab.
  • ARUP notes that latex IgE can cross-react with ragweed and with foods such as banana, avocado, kiwi and chestnut.

When to talk to a clinician

Call 911 or your local emergency number right away for signs of a severe allergic reaction, such as trouble breathing, swelling of the tongue, lips or throat, dizziness or fainting, a fast heartbeat, or cold, clammy skin that looks pale, gray or bluish. Contact a clinician if you get itching, hives or a rash after contact with latex. Mention a positive latex test or past latex reaction before surgery or dental work.

Questions you could ask

  • Should we recheck this, and how often?
  • How do my past reactions fit with this result?
  • Should I let my dentist and surgical teams know, and how?
  • Would tests for related foods or single latex proteins help?

Questions people ask

If my latex result is negative, can I rule out a latex allergy?

Not completely. A negative result makes an IgE-mediated latex allergy less likely, but ARUP notes that a negative blood test may not rule out clinical allergy. If you have had reactions to latex, talk with an allergist about further testing.

Why does my latex result come up with banana, avocado or kiwi?

Some proteins in these foods look like proteins in latex, so IgE made against latex can react with them. This is called latex-fruit syndrome. Having IgE to one doesn't always mean you react to the other.

What do the classes 0 to 6 on my report mean?

Labs sort the number into classes from 0 (negative) to 6 (very high). A higher class means more IgE was found. It does not tell you how strong a reaction would be. The cutoffs differ a little between labs. For example, Quest and ARUP start class 1 at 0.35 kU/L, while Labcorp starts it at 0.32 kU/L.

Show the science and sources

Units

  • 1 kU/L = 1 kU/L
  • 1 kU/L = 1 UA/mL

For clinicians and researchers

Latex IgE (ImmunoCAP k82, Hevea brasiliensis) is measured by fluoroenzyme immunoassay at Labcorp (602669 and 650390) and ARUP (0099614, 'Allergen, Occupational, Latex IgE, Enhanced') and reported in kU/L (LOINC 6158-0). Labcorp lists the expected result as negative. Labcorp describes localized skin reactions after contact, conjunctivitis, rhinitis and asthma after inhalation of airborne particles, and systemic reactions up to anaphylaxis regardless of the route. ARUP notes that latex-specific IgE can cross-react with ragweed and with banana, avocado, kiwi and chestnut, and warns that a negative test may not rule out clinical allergy, even anaphylaxis. Latex proteins are numbered as Hev b allergens, and tests for single proteins (for example Hev b 5 and Hev b 6.02) exist; they can add information in specialist care, for example when cross-reactivity is suspected. Class cutoffs differ between labs.

LOINC 6158-0 (primary), 112120-1, 102400-9. Specimen: serum.

Sources

  1. Latex (test 602669), Labcorp
  2. Sample report for test 602669 (K082-IgE Latex), showing the class table, Labcorp
  3. Allergen, Occupational, Latex IgE, Enhanced (test 0099614), ARUP Laboratories
  4. Latex Allergy, MedlinePlus (National Library of Medicine)
  5. Allergy Blood Test, MedlinePlus (National Library of Medicine)
  6. Food Allergy Testing, MedlinePlus (National Library of Medicine)
  7. VALIDA project: Validation of allergy in vitro diagnostics assays (Tools and recommendations for the assessment of in vitro tests in the diagnosis of allergy), Advances in Laboratory Medicine (2020)
  8. ImmunoCAP Specific IgE Blood Test: Allergy Test List (interpretation table and test codes), Quest Diagnostics (2017)
  9. ImmunoCAP Specific IgE blood test results: Interpretation (respiratory results interpretation guide), Thermo Fisher Scientific (Phadia) (2023)
  10. ImmunoCAP allergy: Change to Reference Interval Interpretation, UR Medicine Labs, University of Rochester Medical Center (2022)
  11. Prevalence of allergic sensitization in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006, Journal of Allergy and Clinical Immunology (2014)

AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.

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