Allergies to Environment

Allergic reactions to environmental allergens

The allergic response to environmental allergens can result in varying symptoms ranging from mild discomfort to life-threatening.

There are different types of allergic reactions that manifest from biological differences and unique properties of different environmental allergens.

IgE-mediated environmental allergies (Type I Hypersensitivity Reactions): ³

This is the most common type of allergic reaction and the IgE antibody plays a major role in the immune response. A reaction usually occurs within seconds to one hour after exposure to an environmental allergen, and rarely, a late-phase reaction can develop four to six hours after the first sign of symptoms.

Mild or moderate allergic reactions to environmental allergens can include the following symptoms:

rash or hives
runny or itchy nose
facial swelling, local swelling at the site of exposure
watery, red, or swollen eyes (conjunctivitis)
abdominal pain, diarrhea, nausea, or vomiting

Symptoms that indicate a severe allergic reaction called anaphylaxis (seek immediate medical attention):

difficulty breathing, tightening of the airways
swelling of the tongue or throat
shock with a severe drop in blood pressure
rapid pulse
dizziness, lightheadedness, or loss of consciousness

Hay Fever²¹

Hay fever, also called seasonal allergies or allergic rhinitis, causes cold-like symptoms of the nose and eyes after exposure to inhaled environmental allergens. Airborne allergens such as pollen, household pests, pets, and mold spores are the most common allergens associated with hay fever.

Symptoms are typically localized to the areas that come in contact with the airborne allergen.

Common symptoms:

Brain Fog (Headache, dizziness, fatigue, inability to think clearly)
Congestion
Cough
Ear pressure, fullness, or pain
Runny and itchy nose
Sneezing
Watery, itchy, red eyes (conjunctivitis)

Non-IgE mediated environmental allergies:

Allergic Contact Dermatitis⁽²²^, ²³⁾

Allergic contact dermatitis is an inflammatory disease of the skin that is caused by contact with environmental allergens.

The immune response against these allergens is led by an allergen-specific T cell population, which causes local symptoms such as an itchy rash, blisters, or swelling of the contacted skin. Symptoms develop within minutes to hours of exposure and can last 2 to 4 weeks.

Mixed IgE/Non-IgE-mediated food allergies:

Eosinophilic Gastrointestinal Diseases (EGIDs):

Food allergens are not the only thing that can trigger EGIDs such as EoE. Environmental allergens such as pollen can be the main cause of EGIDs.

Interaction with immunological barrier disorders:

Both environmental and food allergens can trigger flare-ups of immunological barrier disorders such as asthma, eczema, and irritable bowel syndrome.