Skip to content

5asaigeqn

Published: August 9, 2026Updated: August 10, 2026

This blood test detects allergic antibodies (IgE) against 5-aminosalicylate medications, which are commonly prescribed to treat inflammatory bowel disease.

Quick summary

{"Checks for allergic reactions to IBD medications like mesalamine and sulfasalazine","Performed on a blood sample from your arm","Helps your doctor determine if digestive symptoms are caused by medication allergy","Results guide treatment decisions for ulcerative colitis and Crohn's disease"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 10, 2026Editorial policy

Key facts at a glance

LOINC
98043-3
Short code
5ASA IgE
Synonyms
5-ASA IgE Qn
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or plain red top tube
Units
N/A
Ref low
0.35
Ref high
0.7
Fasting
false
Population
adult
Sex
all
Age range
18–100 years
Method
Immunoassay (Chemiluminescence or ELISA)
CPT
86003
SNOMED
308198006
Specimen volume
1.0 mL serum minimum
Stability
Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days
Hemolysis max
50
Lipemia max
300
Icterus max
20
TAT
24–72 hours
Order
routine

What is this test?

The 5-Aminosalicylate IgE Antibody test is a blood test that looks for IgE antibodies specific to 5-aminosalicylate medications. IgE antibodies are immune proteins that your body produces when you have an allergic reaction. This test helps doctors determine if symptoms like nausea, diarrhea, abdominal pain, or rash are caused by an allergic reaction to certain inflammatory bowel disease (IBD) medications.

What are 5-aminosalicylates?

5-aminosalicylates (also called 5-ASAs) are a class of anti-inflammatory medications commonly used to treat ulcerative colitis and Crohn's disease. Common examples include mesalamine (also called mesalazine or 5-ASA), sulfasalazine, olsalazine, and balsalazide. These medications help reduce inflammation in the digestive tract and maintain remission in IBD patients.

Why is this test performed?

Your doctor may order this test if you are taking or about to start 5-aminosalicylate medications and develop symptoms that could indicate an allergic reaction. Symptoms may include nausea, vomiting, diarrhea, abdominal pain, headache, rash, itching, or difficulty breathing. This test helps distinguish between an allergic reaction and other causes of your symptoms.

How is the test performed?

A healthcare professional will draw a small blood sample from a vein in your arm. The blood is then sent to a laboratory for analysis. The test measures the level of IgE antibodies specific to 5-aminosalicylates in your blood serum. No special preparation like fasting is typically required before this test.

What do the results mean?

A positive result means that IgE antibodies against 5-aminosalicylates were detected in your blood, suggesting you have or are developing an allergic reaction to these medications. A negative result suggests no detectable allergic antibodies, though this does not completely rule out other types of reactions or intolerance. Your doctor will interpret these results along with your symptoms and medical history to determine the best treatment approach.

Reference range

Negative: <0.35 kU/L; Equivocal: 0.35-0.70 kU/L; Positive: >=0.70 kU/LN/A

Specimen: serum

No special preparation required. Inform laboratory of current medications, especially antihistamines or corticosteroids that may affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings2

Frequently asked questions

Who needs this test?
This test is recommended for patients with ulcerative colitis or Crohn's disease who are taking or will be taking 5-aminosalicylate medications (such as mesalamine, sulfasalazine, or olsalazine) and develop symptoms that could indicate an allergic reaction.
Do I need to fast before this test?
No, fasting is not required for this test. You can eat and drink normally before having your blood drawn.
How long does it take to get results?
Results are typically available within a few days to a week, depending on the laboratory. Your healthcare provider will contact you with the results or discuss them at your follow-up appointment.
What happens if my test is positive?
If positive, your doctor will likely recommend discontinuing the 5-aminosalicylate medication and switching to an alternative treatment for your IBD. This may include other anti-inflammatory medications, corticosteroids, immunomodulators, or biologic therapies depending on your condition.
Can I still develop an allergy even if this test is negative?
Yes, a negative result does not completely rule out an allergic reaction. Some allergic reactions may involve different immune pathways or may not yet have produced detectable IgE antibodies. If your symptoms persist, your doctor may recommend additional testing or a supervised medication challenge under medical supervision.
  1. 1
    Mayo Clinic - Ulcerative Colitis TreatmentSource
  2. 2
    Crohn's & Colitis Foundation - MedicationsSource
  3. 3
    National Library of Medicine - 5-AminosalicylatesSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 10, 2026. · Read our editorial policy