From the Guidelines
A non-IgE allergy is an allergic reaction that occurs without involving immunoglobulin E (IgE) antibodies, which are typically responsible for immediate allergic responses, and the best management plan for these reactions is to avoid ingesting the specific allergen or allergens, as recommended by the NIAID-sponsored expert panel 1.
Key Characteristics of Non-IgE Allergies
- These reactions are mediated by other immune mechanisms such as T cells or other antibody types like IgG.
- Common examples include certain food intolerances, contact dermatitis, and some drug allergies.
- Symptoms may develop more slowly than in IgE-mediated allergies, sometimes taking hours or days to appear, and can include rashes, joint pain, fever, or gastrointestinal issues.
Diagnosis and Management
- These reactions can be more difficult to diagnose since standard allergy tests like skin prick tests or RAST tests specifically detect IgE antibodies and may not identify non-IgE allergies.
- Management typically involves avoiding the triggering substance and treating symptoms with antihistamines, corticosteroids, or other anti-inflammatory medications as needed, as suggested by the guidelines for the diagnosis and management of food allergy in the United States 1.
- In some cases, specialized testing such as patch testing or elimination diets may be required to identify the specific triggers, considering the medical history, the age of the individual, and the specific food allergen 1.
Importance of Understanding Non-IgE Mechanisms
- Understanding these non-IgE mechanisms is important because they explain why some allergic reactions don't follow the typical immediate pattern and may require different diagnostic approaches.
- The literature cannot readily be divided on the basis of IgE-mediated and non-IgE-mediated reactions, but the management of non-IgE-mediated food allergy is similar to that of IgE-mediated FA, in that the medical history, the age of the individual, and the specific food allergen are all-important considerations in developing the management plan 1.
From the Research
Definition of Non-IgE Allergy
- A non-IgE allergy, also known as a non-immunoglobulin E-mediated food allergy, is a type of food allergy that does not involve the immunoglobulin E (IgE) antibody 2, 3, 4, 5, 6.
- This type of allergy is characterized by delayed gastrointestinal manifestations that occur after exposure to an inciting food protein 3.
Types of Non-IgE Allergies
- Food protein-induced enterocolitis syndrome (FPIES) 3, 4, 6
- Food protein-induced allergic proctocolitis (FPIAP) 3, 4, 6
- Food protein-induced enteropathy (FPE) 3
- Eosinophilic esophagitis (EoE) 2, 4, 6
- Food protein-induced dysmotility disorders (GORD and constipation) 4
Diagnosis and Management
- Diagnosis of non-IgE-mediated food allergies can be challenging due to the lack of noninvasive confirmatory tests or biomarkers 3, 4, 6.
- Diagnosis is usually made clinically, and relies on a constellation of typical symptoms that improve upon removal of the culprit food 3, 4.
- Management includes dietary avoidance, supportive treatment in the case of accidental exposure, and nutritional counseling 4, 6.
- Treatment of non-IgE food allergy is dependent on diet and/or use of drugs (i.e. steroids, PPI) in EoE and Non-EoE EGID 6.