IgE is an antibody found in the blood that is a marker for allergy diseases. People who have elevated IgE levels can have environmental or food allergies. If you get a blood test and it shows that you have an elevated IgE that could mean you are an allergic patient. A total elevated IgE just tells you that you have a high chance of allergies, but it does not tell you specifically what you are allergic to. Your doctor may then send you for specific IgE testing. This can be done as an allergy skin test by an allergy doctor, where the allergist will prick your skin with different outdoor triggers, such as tree pollen, grass pollen and weed pollen. Or with indoor triggers such as dust mites, cat, dog or mold (this can be outdoor or indoor). This is not an extensive list, as there are many more environmental triggers. A blood allergy test too can help confirm a specific environmental allergy to help figure out why there is an elevated IgE level.
An elevated IgE level can also represent a food allergy, the most common food allergies are wheat, milk, soy, eggs, tree nuts, peanuts, shellfish and fish. These foods can also be tested via an allergy skin test, by an allergy doctor or an allergy blood test.
However there are some cases where there is an elevated total IgE, but the specific IgE (environmental or foods) are negative. If the allergy skin testing is negative or the blood allergy test is negative to the specific allergens, there could be other causes of the elevated IgE.
1. Parasitic diseases such as ascariasis, hookworms, visceral larva migrans. People traveling to underdeveloped countries and drinking unclean water supplies are at risk.
2. Infectious diseases such as Allergic Bronchopulmonary Aspergillosis (ABPA), systemic candidiasis, EBV, CMV, Leprosy, RSV or HIV-1. This is not a comprehensive list and one should consult with a doctor regarding this.
3. Neoplastic diseases such as Hodgkin’s disease, IgE myeloma, post bone marrow transplant, bronchial carncinoma.
4. Immunodeficiency Diseases- Wiskott-Aldrich, Hyper IgE, DiGeorge’s syndrome.
5. Cutaneous Diseases-Bullous pemphigoid, chronic acral dermatitis, streptococcal erythema nodosum.
6. “Other diseases”- Nephrotic syndrome, Nephritis, liver disease, Cystic Fibrosis, Kawasaki Disease, Guillain-Barre syndrome.
Overall most people who have an elevated IgE level will most likely have some type of specific allergy. Specific allergy testing for an elevated IgE will help identify what exactly they are allergic to. If specific allergy testing from skin testing or blood testing does not identify any allergies, then you should consult with your allergy doctor regarding any other possibilities for an elevated IgE level.
According to Quest Diagnostics, the normal reference range for total IgE levels is below.