An IgG allergy, more accurately described as an IgG-mediated food sensitivity or delayed hypersensitivity, is a type of delayed inflammatory reaction in the body, unlike the immediate reactions of a traditional IgE allergy.
Understanding IgG Reactions
IgG reactions are often confused with IgE allergies because both involve the immune system. However, their mechanisms and symptoms are significantly different:
| Feature | IgE Allergy | IgG Reaction |
|---|---|---|
| Reaction Time | Immediate (minutes to hours) | Delayed (hours to days) |
| Primary Antibody | IgE | IgG |
| Symptoms | Hives, swelling, anaphylaxis | Inflammation, digestive issues, behavioral changes |
| Mechanism | Mast cell activation | Complex immune pathways involving inflammation |
Key Characteristics of IgG Reactions:
- Delayed Response: As the provided reference mentions, IgG responses are delayed, meaning symptoms do not appear immediately after exposure to a trigger substance.
- Inflammatory in Nature: These reactions involve inflammation and can affect various parts of the body. The provided reference notes this inflammatory aspect.
- Broad Range of Symptoms: Symptoms are varied and can include:
- Digestive problems, such as bloating, gas, and changes in bowel habits.
- Skin issues like eczema or rashes.
- Joint pain and muscle aches.
- Fatigue and general malaise.
- Behavioral changes, particularly in children, as the provided reference suggests.
IgG Testing:
While IgG tests for food sensitivities are available, their accuracy and clinical relevance are debated within the medical community. The interpretation of results should be done with the help of a qualified professional. These tests measure the IgG levels in blood in response to different food proteins, but the presence of IgG doesn't always equate to a food allergy.
Practical Insights:
- Identifying Triggers: Due to the delayed nature of symptoms, identifying the specific triggers for IgG reactions can be challenging. Keeping a detailed food diary and symptom log might help.
- Elimination Diets: An elimination diet, guided by a healthcare professional, is sometimes used to identify offending foods by temporarily removing them and then reintroducing them one at a time.
Important Note:
It is critical to differentiate IgG reactions from IgE-mediated allergies which can be life threatening and require a proper diagnosis and management.
