An Allergic reaction is an immune system response to a foreign substance that is not typically harmful to your body. The harmful substances which can elict an allergic response including certain foods, pollen, or pet dander. Allergic reaction response can be different and, it all depends on the allergen.
Why do Allergic Reactions happen?
The job of immune system is to defend the body from the harmful substances like viruses and bacteria. However, to body is allergy.the reaction against a substance, which is not causing any harm . antibodies are released during reaction. Antibodies are proteins that deliver a message to cells. The cells then send out histamine, which causes blood vessels to expand, and other chemicals, and these trigger the allergy symptoms.
Why we are allergic to one type of allergen and not to another?
Each antibody targets only one type of allergen. which explains why someone might be allergic to peanuts but not to eggs.
Symptoms of an allergic reaction: From Itchy Eyes to Sneezing
Allergic symptoms can be different from one person to another but mainly depends on the type of allergen causing the harm.
For food allergies
Food allergies can trigger swelling, hives, nausea, fatigue, and more. Realization of food allergy is late. However, Hay fever symptoms can mimic those of a cold.
For severe allergies
Anaphylaxis can occur during severe allergies. Anaphylaxis causes severe breathing difficulty.including loss of conciousness.
Skin allergies may be a sign or symptom of an allergy. They may also be the direct result of exposure to an allergen. Skin disorders can also occur.
Types of allergic reactions
There are four types of allergic reactions.
- Type1 or anaphylactic reaction
IgE antibodies play imporatant role in Type 1 reaction and mimic the immune response. Production occurs in response to allergen. Thus, release of inflammatory chemicals like histamine occur in the body. Examples of type I allergic reactions include
- Bronchial asthma,
- Allergic rhinitis,
- allergic dermatitis,
- food allergies,
- Allergic conjunctivitis (eye inflammation)
- Anaphylaxis (allergic shock)
Type 2 or cytotoxic reaction
IgM antibody mediate this response in the body. Complement system is activated by antibodies, which destroy the cell of allergen. Type II allergic reactions can be seen in certain conditions like
- autoimmune neutropenia
- immune thrombocytopenia and
- autoimmune hemolytic anemia
- Type 3 or immunocomplex reaction
IgM and IgG antibodies mediate this response. Immunocomplexes is formed by the interaction allergen and antibody. (antigen-antibody complexes). The complexes are responsible for the reaction. Type III allergic reactions can be seen in,
- Arthus reaction.
- Serum sickness
- Type4 or cell-mediated reaction
Type IV allergic reactions are also called the delayed type of hypersensitivity or allergic reactions. They occur after at least 24 hours of exposure to the allergen. $8-72 hours is taken by this types to show the symptoms.
What are the triggers of allergic reactions? or What are the causes of an allergic reaction?
Substances that trigger an allergic reaction include:
- Dust mites
- Animal/pet dander
- Bee/wasp stings
- Certain medications such as penicillin
- Certain foods such as soy, eggs, peanuts,
- Certain metals
Risk factors for an allergic reaction.
You might be more likely to encounter an allergic reaction if you:
- Have a family history of asthma or allergies, such as hay fever, hives, or eczema
- Are a child (as children not immune to many types of allergens at the beginning of their life)
- Have asthma or another allergic condition
How is an allergic reaction diagnosed?
The Doctor can diagnose allergic reactions. The doctor may want to order tests to determine what’s causing your allergy. The most commonly ordered types of allergy tests are:
- skin tests
A skin test is most valuable for diagnosing:
- food allergy (like shellfish or peanuts)
- mold, pollen, and animal dander allergy
- penicillin allergy
- venom allergy (such as mosquito bites or bee stings)
- allergic contact dermatitis (a rash you get from touching a substance)
- challenge (elimination-type) tests
- blood tests
How can you prevent an allergic reaction?
Once you identify your allergy, you can:
- Avoid exposure to the allergen.
- Seek medical care if you’re exposed to the allergen.
- Carry medications to treat anaphylaxis.
Allergic reaction can’t be completed avoided completely. However, the symptoms can be decreased be prevention and care.
Treatment of allergy
If you don’t know the cause of your allergy, you may need to see your doctor. The rescue drug epinephrine is used during emergency cases, as it opens the airway. If the person is unconscious, you should:
- Lay them flat on their back.
- Elevate their legs.
- Cover them with a blanket.