From the Guidelines
A serum IgE level of 18.6 IU/mL is within the normal reference range for adults, which typically falls between 0-100 IU/mL, and suggests that you do not have elevated IgE levels that would indicate an allergic condition or other IgE-mediated disorder. This result is based on the most recent and highest quality study available, which emphasizes the importance of interpreting IgE levels in the context of clinical symptoms and medical history 1. It is essential to note that a normal IgE level does not completely rule out allergies, as some individuals can have normal total IgE levels but still have specific allergies that would be detected through allergen-specific IgE testing.
Key Points to Consider
- IgE levels should always be interpreted in the context of clinical symptoms and medical history, as a normal level does not necessarily exclude the presence of allergies 1.
- Allergen-specific IgE testing may be necessary to identify potential allergens, even with a normal total IgE level 1.
- The presence of sIgE reflects allergic sensitization and not necessarily clinical allergy, and the predictive values associated with clinical evidence of allergy may vary depending on the test method and population being studied 1.
- Clinical symptoms and medication use are better markers of effective allergy treatment than repeat allergy testing, and clinicians should avoid routine use of repeat allergy testing to assess treatment efficacy 1.
Implications for Clinical Practice
- Clinicians should interpret IgE levels in the context of clinical symptoms and medical history, rather than relying solely on the test result.
- Patients with normal IgE levels who are experiencing allergy symptoms should be considered for allergen-specific IgE testing to identify potential allergens.
- Treatment efficacy should be assessed based on clinical symptoms and medication use, rather than repeat allergy testing.
From the Research
Interpretation of Serum Immunoglobulin E (IgE) Level
The interpretation of a serum Immunoglobulin E (IgE) level of 18.6 is not directly addressed in the provided studies. However, the studies provide information on the normal and elevated levels of IgE and their associations with various conditions.
Normal and Elevated IgE Levels
- Elevated serum IgE levels are associated with allergic disorders, parasitosis, and specific immunologic abnormalities 2.
- IgE levels can be influenced by various factors, including genetic and environmental factors, and can be used as a marker for different disorders 2.
- High-titer IgE antibodies are characteristic of certain food allergies, such as peanut and galactose α-1,3-galactose (alpha-gal) allergy 3.
IgE Levels in Atopic Dermatitis
- In a study of 154 patients with atopic dermatitis (AD), total IgE levels were significantly different between mild, moderate, and severe forms of AD patients, with higher levels in severe AD patients 4.
- The study also found that AD patients with accompanied allergic diseases showed significantly higher total IgE levels than those without accompanied allergic symptoms 4.
Clinical Significance of IgE Levels
- IgE levels should be interpreted in combination with clinical history to avoid unnecessary food avoidance 4.
- The presence of specific IgE antibodies can play an important role in identifying the relevant allergen and providing a guide to therapy in cases where the relationship between exposure and disease is not clear 3.
It is essential to note that the provided studies do not provide a specific reference range for IgE levels, and the interpretation of an IgE level of 18.6 would depend on the individual's clinical context and the reference range used by the laboratory that performed the test.