News & Blogs
July 09 2020

Allergic Reactions: How Do They Happen?

Dust, pollen, insect stings, mold, food, and other allergens can trigger a sudden allergy attack or allergic reaction. Its manifestations can come in various forms, such as sneezing, stuffy or runny rose, skin irritation, and sore throat, among others, which can be extremely unbearable in some cases.
Everyone’s body is different, and the immune system’s response to an allergen may be different from another person’s reaction. For instance, one person’s mild reaction to an allergen could trigger a severe attack on another.
Allergies are one of the most common health issues that affect people of all ages. Below are some interesting facts and statistics to put into perspective the prevalence of allergic diseases.
  1. Globally, adverse drug reactions may affect about 10% of the world’s population and up to 20% of all hospitalized patients.
  2. Allergies rank 6th among other leading chronic diseases in the U.S.
  3. In the U.S., allergies affect 30% of adults and 40% of children.
  4. Around 40 people die in the U.S. every year due to allergic reactions to bee stings.
  5. Around 10% of the U.S. population is allergic to pets, and cats are often the culprits.
  6. One study shows that 97.4% of Filipinos exhibit a sensitive response to indoor allergens, with another 86.9% to outdoor allergens.
  7. Food allergy affects roughly 2.5% of the general population.
  8. In 2010, there were about 9.4 million reported cases of skin allergies in children.
What is an allergic reaction?
An allergic reaction is the body’s immune system response to fight off foreign elements that are deemed as harmful invaders (even when they are not), like a particular food or substance. These triggers are called allergens, and they can be anything from dust to medication. When the body gets exposed to allergens, it can trigger an allergy attack.
Allergies are more common in children. Some allergies subside and disappear as a child grows older, but many persist throughout their lives. Having an allergy can affect one’s daily routine or activities.
Allergic reactions often happen fast, which may be within a few minutes after exposure to an allergen, and symptoms can vary from mild to severe.
Common symptoms include:
  1. Stuffy, runny nose, or nasal congestion
  2. Scratchy throat
  3. Hay fever, also called allergic rhinitis, causes sneezing, watery eyes, and itching (often triggered by pollen or dust allergens).
  4. Conjunctivitis or itchy, red, and watery eyes
  5. Swollen lips, tongue, eyes, face, or contact area
  6. Raised, itchy, red rashes on the skin (hives)
In some cases, allergies can lead to anaphylaxis, which is a reaction to severe allergies and is a life-threatening condition. Symptoms of a severe allergic reaction include:
  1. Swelling of the face, eyes, or tongue
  2. Flushing of the face
  3. Wheezing and difficulty breathing
  4. Heart palpitations
  5. Nausea or vomiting
  6. Abdominal pain or cramping
  7. Weakness
Types of Allergies
Allergies come in different types. Some are seasonal, and others last year-round. However, there are those that last for a lifetime. Here are the most common types:
1. Skin Allergy - The kind of allergic reaction when the skin comes into contact with an allergen is called contact dermatitis. The skin condition can be triggered when a person has a nickel allergy and wears jewelry that contains it. This can also happen with poison ivy or even when using a new brand of laundry detergent. Symptoms include itchy, swollen, scaly, or bumpy skin.
2. Food allergy - Eggs, milk, fish, tree nuts, soy, wheat, shellfish, and peanuts are responsible for more than 90% of all reported food allergies. A food allergy reaction may manifest in the skin or involve the respiratory tract, cardiovascular system, and gastrointestinal tract.
3. Pollen allergy - Pollen is a common trigger of seasonal allergies affecting over 25 million Americans. Grasses, oak trees, and ragweed are known to produce highly allergenic pollen. This is also referred to as hay fever and “seasonal allergic rhinitis.”
4. Pet allergy - Allergic reactions to pets with fur like cats and dogs are common, but cat allergy is twice as common. People with pet allergies react to the pet’s urine, saliva, or dander (tiny flecks of skin).
5. Insect allergy - Bees, fire ants, wasps, hornets, and yellow jackets, are the most common stinging insects that can trigger an allergy attack. Cockroaches, fleas, mosquitoes, and other non-stinging insects are also known to cause an allergic reaction.
6. Drug allergy - While most drug reactions are side effects to the components of the medicine, adverse reactions to drugs occur to a small number of people. Individuals with a drug allergy have a highly sensitive immune system, and the diagnosis is usually based on the patient’s history and symptoms.

There are two ways to diagnose an allergy:
1. Skin prick test - This is the most common allergy test and provides the fastest, most accurate results. This is done by putting a tiny drop of liquid that contains an allergen on the forearm, then the outer layer of the skin will be gently pricked or scratched to see a reaction. If the area swells up and turns red, it means the patient is allergic to that substance.
2. Blood test - The patient undergoes blood testing to identify an allergy if a skin test cannot be done. A sample of the blood is taken and analyzed for specific antibodies generated by the immune system in response to an allergen.

Mild allergic reactions can be treated with over-the-counter medications. Below are the commonly used treatments that alleviate the symptoms of an allergy attack.
  • Antihistamine - This medication can treat minor allergic reactions and reduces the common symptoms like watery eyes, stuffy or runny nose, skin reactions, and sneezing. Antihistamines come in different forms, such as oral pills, nasal sprays, eye drops, liquids, and dissolvable tablets.
  • Nasal decongestant - To help reduce symptoms like swollen sinuses, sore throat, and stuffy nose, the person can use nasal decongestants like pills, liquids, and sprays. Note that decongestant medications must not be taken continuously for over 72 hours or as prescribed by the doctor.
  • Anti-inflammatory medications - For any swelling, cramping, and pain caused by allergic reactions, non-steroidal anti-inflammatory medications (NSAIDs) can temporarily relieve these.
Naturally, the best way to prevent allergic attacks is to determine the triggers and avoid them, especially with food allergens. If necessary and the symptoms are severe, head to the nearest emergency room for immediate treatment.
Allergens can disrupt one’s daily life and stealthily attack through food or the environment. Everyone should know what to do when someone else experiences an allergic reaction.
If you experience nasal drainage, recurrent sinusitis, coughing, or conditions affecting the ears, nose, and throat, go to an allergologist for a consultation or go straight to an allergologist. It is important to consult with a doctor to identify if you have an allergy or create a plan to manage it. You can contact the Makati Medical Center for urgent health concerns about allergies.