Will you be (hista)mine?: Body talk and allergy medications

“I didn’t know it was [made from shrimp],” narrates Noelle Gloria (I, AB-ISJ), referring to one New Year’s Eve when she was hospitalized after eating a serving of bagoong. She recalls that allergic reactions manifested in the form of numbing hands, difficulty of breathing, and shaking of the body despite taking Claritin, a brand or trade name of loratadine, a form of antihistamine—an anti-allergy medicine that targets the production of a chemical compound called histamine.

Naturally, irritants or substances that elicit inflammatory reactions in the body differ for each person. Typically harmless substances in the environment that can irritate one’s immune system and cause the body to overreact, allergens are what mostly cause allergy attacks, which vary in intensity and symptoms. 

No matter how cautious one is, however, there are instances when one cannot avoid encountering objects that trigger an allergy. 

Tricky situations

On occasions such as Valentine’s Day, some are in danger of being exposed to irritants such as flowers, with roses, sunflowers, and lilies among the most popular. However, some are unaware that they carry with them small but potent allergens: pollen. 

A powder-like substance, pollen holds a key role in reproduction among plants. Wind can easily carry pollen across distances because of its light weight. If inhaled, it is possible for one’s immune system to identify it as a threat to the body. The body then begins an allergic reaction as a defense mechanism, with one of the most common being allergic rhinitis or hay fever—characterized by sneezing, a runny nose, and itchy and watery eyes.

Allergic reactions occur when the immune system produces histamine—a chemical compound that encourages blood circulation and causes inflammation—after a foreign substance enters the body. If a person were to come into contact with poison ivy, the body would release large amounts of histamine to combat the toxins from urushiol, which is a resin found in the plant that irritates the skin and causes rashes.

Scratching the surface

For Lyra Bognot (I, AB-ISJ), she experiences allergic reactions from changing weather, particularly to  the cold. “Hives appear on the skin on my leg when there is a change in weather conditions,” she explains. When the reaction gets difficult to bear, Bognot says she takes an antihistamine.

Dr. Eligio Maghirang, a physician and associate professor from the Biology Department, explains that each person’s genes—biological molecules passed down from parent to child that influence the development of different physical traits, such as height, blood type, and risk for disease—are involved in determining whether an allergic reaction is inherited or acquired, if it can be treated, when it will surface, and for how long it may affect the person.

“It’s an immune response,” Maghirang explains. “We have our own set-up, our own genetic makeup.” 

It is possible, however, for a person to grow out of an allergy if they are exposed to very low doses of the substance over a long period of time. A drug is currently under development in the United States to help patients with peanut allergies by gradually exposing them to small amounts of the peanut proteins that cause allergic reactions, until eventually they can develop a tolerance to the allergen.

But an allergy may also surface after a certain amount of time and exposure, even if one was not previously allergic to that substance. Many develop lactose intolerance later in life because their bodies stop producing lactase, an enzyme that breaks down lactose or milk sugar. “Asians don’t drink a lot of milk. Or some, genetically, would only produce the enzyme lactase for a certain [limited] number of decades,” Maghirang says.

Other common allergens include insect stings, pet dander, certain drugs, and food such as shellfish, soy, cheese, chocolate, and wheat. For food allergies, various proteins may cause an allergic reaction; for example, a person may be allergic to a protein found in egg yolks, but not in egg whites. 

Addressing the itch

To identify whether a person is allergic to certain substances or not, doctors use allergy tests involving skin patches and injections. Though it may be difficult to avoid some allergens such as latex—the source of rubber—these tests may be useful in determining whether antihistamine medication will effectively treat a reaction.

Because allergens can evoke an outpour of histamine into the bloodstream, antihistamines are designed to block the allergic reactions from occurring; specifically, they deactivate histamine receptors⁠—protein structures that histamine molecules bind to in order to stimulate a reaction in some part of the body. Depending on the type and generation of antihistamine ingested, people who suffer from allergies may experience varying side effects.

Maghirang explains that older antihistamines tend to interact with many receptors, not just those specifically for histamine. First-generation medications include diphenhydramine and doxylamine, which are found in brands such as Benadryl and Nyquil. As they are able to enter the brain from the bloodstream, these can cause drowsiness as they hinder another function of histamine, sleep regulation.

Second-generation antihistamines such as loratadine and levocetirizine, on the other hand, were created to target specific histamine receptors in order to prevent any side effects. These medications are also less likely to cross the blood-brain barrier, thus avoiding interfering with histamine’s neural functions. Brands such as Claritin and Allerzet fall under this category.

Some people however, may be allergic to the antihistamines themselves. This could cause anaphylactic shock which is a serious allergic reaction that could lead to organ failure and death. Maghirang recounts a time when he experienced such a reaction. “They had to give [me] an antidote that would kick the antigen out so that the normal processes can continue,” he says. “You have to [administer the antidote] immediately. Real time ‘yun; the allergen is still there.”

Maghirang stresses that allergies happen as the body’s natural response to a potential threat. Although at times, these reactions may become life-threatening. “Your system was exposed to [substance] and it was flagged somehow by your body that it was toxic. It’s a defense mechanism,” he says. Maghirang advises that the best way to prevent an allergic reaction is to “identify your allergen and to stay away from it.”

By Melissa Reyes

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