Symptoms of Allergies and Allergic Reactions

10. Types of Allergic Reaction Symptoms

Renowned British immunologists, Gell and Coombs, classify allergic reactions into four types:

Type 1 (anaphylactic reactions or IgE-mediated)

Type I allergy happens when the body produces IgE antibodies in response to allergens like dander, pollen, and food. Symptoms like anaphylaxis, nausea, angioedema, and spasm manifest almost instantly after exposure to the allergen.

Type II (cytotoxic reactions)

With type II allergies, the body produces IgM and IgG antibodies. These antibodies cause cell damage by activating the complement system within the larger immune system. This occurs in people with autoimmune conditions like hemolytic anemia, neutropenia, and immune thrombocytopenia.

Type III (immunocomplex reactions)

Like type II allergies, IgM and IgG antibodies cause type III allergic reactions when these antibodies will bind with the allergen or antigen. Type III allergy usually manifests in people with Arthus reaction, lupus, or serum sickness.

Type IV (immunocomplex reactions)

Also known as the delayed type of allergic reaction, type IV allergy symptoms typically manifest 48 to 72 hours after exposure. This type of reaction does not involve antibodies. Instead, activated T-cells release cytokines, which cause tissue injury due to their vigorous immune response. People with tuberculosis, drug allergies, and contact dermatitis have this type of reaction.

Many different allergies can cause each of these reaction types, and it is important to see a doctor for a proper diagnosis.