Everything You Need to Know About Allergies

An allergy is an immune system response to a foreign substance, or allergen, that’s not typically harmful to the body. Symptoms and treatments may vary depending on the type of allergy you have.
The immune system is responsible for keeping you healthy by fighting harmful pathogens.

It does this by creating antibodiesTrusted Source called immunoglobulin. There are several types of immunoglobulins, which fight against possible agents like bacteria, viruses, parasites, and chemicals. Immunoglobin E (IgE) is a type that responds to certain substances and causes an allergic reaction.
Allergic reactions may involve a variety of symptoms, ranging from mild inflammation to life threatening situations.
Keep reading to learn more about the types, symptoms, and causes of allergies, as well as how to treat them.

When to get immediate medical attention
Sometimes, allergic reactions may cause symptoms that could be life threatening, known as anaphylaxis.
If you or someone you know suddenly experiences any of the following symptoms, call 911 or get immediate medical attention:
• swelling in the face, throat, and tongue
• dizziness, confusion, fainting
• difficulty breathing, swallowing, and speaking
• wheezing or coughing
• skin discoloration, such as blue, pale, or gray tongue

If you or the person has an epinephrine autoinjector, use it immediately. The shot counters allergic reactions until medical help arrives and could be lifesaving.
Types of allergies
There are several types of allergies, according to Allergy UK. These include:
• food allergies
• hayfever (allergic rhinitis)
• asthma
• atopic dermatitis (eczema)
• skin allergies
• medication allergies
• insect bite allergies

Symptoms of allergies
Symptoms of allergies may depend on several factors, such as the type and severity of your allergy.
According to the American College of Allergy, Asthma, and Immunology (ACAAI), common allergy symptoms may include:
• congestion
• runny nose
• sneezing
• coughing
• fatigue
• headaches
• rashes, such as hives
• nausea
• vomiting
• fever
• wheezing
• difficulty breathing

Skin allergy symptoms
Certain skin symptoms may indicate an allergic reaction.
For instance, you may experience tingling in your mouth after eating a food you’re allergic to. Or, you may experience an allergic reaction if your skin comes into direct contact with an allergen, known as contact dermatitis.

Symptoms of skin allergies may include:
• rashes
• hives
• swollen, watery, or puffy eyes
• itching
• burning

Causes of allergies
It’s still unclear why the immune system causes an allergic reaction when a normally harmless foreign substance enters the body.
However, researchers have identified several factors that may contribute to allergies, including:
• older age
• genetics
• hormonal changes, especially in people assigned female at birth
• immunological factors, such as weakened immune system
• gut microbiome changes
• having other allergies, such as atopic dermatitis

How allergies are diagnosed
A doctor will first ask about your symptoms and perform a physical exam.
To confirm an allergy, they may order several tests, including:
• Blood test: This can help detect the presence of IgE, which are cells that react to allergens.
• Skin prick test: Small amounts of an allergen are pricked, brushed, or scratched against your skin to see if there’s an allergic reaction.

Allergy treatments
Avoiding the allergen that triggers the reaction is the best way to prevent allergies. If that’s not possible, there are treatment options available.
Medication
Immunotherapy
Emergency epinephrine
Natural remedies