Tag Archives: allergies

Depression And Allergies

More and more, researchers are starting to see a connection between allergies and depression. There is evidence of relationships in both directions, so allergies exacerbate depression, while depressive symptoms and affect make allergy symptoms worse. One study found that this connection is partly responsible for an uptick in suicides as winter turns into spring. Part of this is a hope that depression is merely seasonal being dashed—people tough it out through the winter but go into a decline when spring doesn’t bring improvement—but now it appears that allergens increasing in the springtime also bears on this phenomenon.

Depression is thought of as a mental illness, but the brain is part of the body, and there’s no bright line, medically speaking, between physical symptoms and mental ones. One place where this is apparent is allergic reactions causing depressive symptoms. Allergens are normally harmless substances, such as pollen, that trigger an immune response in people who are sensitive to them. Part of this immune response is inflammation. Inflammation can lead to a low feeling called dysthymia; this is why people who are sick feel awful. Dysthymia is also a symptom of depression. Some scientists have proposed that a hitherto underestimated cause of depression itself is inflammation due to allergy.

Meanwhile, stress is both a cause and an effect of depression. Depression can be a response, in part, to stress, but t can also increase it. Stress is also intimately bound up with the immune system The stress hormone cortisol temporarily suppresses the immune system, only for it to come back turned up after the stressor has passed. That means that stress, anxiety, and depression actually make allergic reactions worse, particularly on the second day. That means not only does stress directly lead to depression, it also increases depression as a result o the inflammation from an allergy attack.

In children, scientists have also found a genetic link between allergies and depression, as well as behavioral problems. While allergies themselves exacerbate depression, and allergies and depression alike are partly responsible for children misbehaving, there is evidence that genetics is behind a predisposition to allergies, a predisposition to depression, and a tendency to act out.

Mold In Buildings

Just as a house is a nice cozy home for a family, the warm, moist interiors of its walls are a nice cozy home for mold. Unfortunately, the mold can be bad for the family’s health. The plants, fungi, and other tiny organisms collectively known as mold include allergens that can be uncomfortable or even harmful in the close quarters of a home or office. Though mold normally live outside on organic matter such as dead trees and fallen leaves, spores can get blown in through open doorways and windows, or brought in by air intakes. Once in the home, they attach themselves to damp surfaces and start to grow, develop, and reproduce.

This isn’t always bad. After all, it was a mold, Aspergillus penicillium, that changed modern medicine, spurring the invention of antibiotics, which made untreatable and often fatal diseases manageable for the first time in history. However, even A. penicillium can cause quite severe allergic reactions in some people. Other types of mold are even less beneficial. One of the most common, Trichoderma longibrachium, is also one of the most potentially dangerous. It produces a toxic substance called trilongins. When absorbed by the body, this prevents cells from getting the potassium and sodium they need. Potassium and sodium are important for circulation and respiration, when they are rendered inert, it can disrupt the heart and the lungs.

There is no real cure for symptoms caused by mold exposure. As long as the person is exposed to mold—such as at home, or at the office—the symptoms will come back even if treatment is provided. The only solution is to remove either the patient or the mold from the environment. Getting fresh air in will help dry out the damp areas molds look for. In humid weather, a air conditioner or a dehumidifier will keep things dry. Anti-mold cleaners will help in places like the bathroom.

However, researchers are looking for a way mold allergy can be treated, for example when removal is not possible or practical. One surprising finding was that vitamin D can actually help prevent mold allergies. Patients in that study with allergies had low vitamin D levels, and when they were administered the vitamin, their allergic reaction lessened and the allergy itself—the tendency to have that reaction—was diminished.

Dangerous Allergies

When someone with an allergy to something comes into contact with whatever it is, it causes an allergic reaction. A common type of allergic reaction, affecting as many as 15 percent of the population, is called anaphylaxis or, when it is sudden and severe, anaphylactic shock. People experiencing an anaphylactic reaction will experience itching, a tightening of the throat and swelling of the tongue which make breathing difficult, dizziness, a rapid pulse, and nausea or diarrhea.

Anaphylactic shock can be dangerous, even fatal. In fact, anaphylactic shock kills about 1,000 Americans each year. It is generally the result of a food or medicine allergy—the "Big Eight" allergens are milk, eggs, fin fish, shellfish, tree nuts, peanuts, wheat and soy, and penicillin allergies are common—or bee or wasp stings, though it can result from a variety of factors, including latex and even exercise. The reaction often gets more severe with each exposure.

Now researchers say a new discovery gives a clearer picture of the causes and mechanisms behind anaphylaxis than ever before. The reaction involves a chemical, platelet-activating factor, released by cells as part of the immune response, sch as to an allergen. Ordinarily, this chemical is broken down shortly after it is produced and has done its work by a enzyme called PAF acetylhydrolase. When someone is having an allergic reaction, PAF is released despite there being no actual need for an immune reaction. In addition, in some people, there are low levels of PAF acetylhydrolase, meaning it breaks down PAF more slowly. The researchers found that people with the most severe anaphylactic reactions were the people with the lowest levels of PAF acetylhydrolase.

The best way to prevent anaphylaxis is to avoid thing that trigger it, though that can be difficult for people who’ve never had a reaction to anything before. An allergy to one thing doesn’t necessarily mean an allergy to anything else, but as the immune system develops a response to a particular trigger, the reaction tends to get worse as more PAF is produced each time. People who know they are prone to allergic reactions should always have epinephrine available; the hormone, which when administered immediately can help attenuate the reaction, is available in auto-injection pens. A person who has had an anaphylactic reaction needs emergency care even with a pen.

Finding Food Allergies

An estimated four percent of people have a food allergy of some sort. Almost any food or ingredient can cause an allergic reaction in someone who is sensitive to it, but the most common culprits—collectively responsible for as many as 90 percent of severe allergic reactions to food—are the so-called Big Eight: cow’s milk, eggs, peanuts, tree nut such as almonds and pecans, fish, shellfish, soy, and wheat. Unfortunately, these are quite common ingredients in commercially available foods—indeed, without specifically looking, it’s difficult to fill a cart with only products that use none of these—and some, such as eggs and shellfish, have medical applications as well.

There has seemed, in recent years, to be a rise in food allergies. There are several factors at play in this. As more and more manufacturers and restaurants are accommodating allergies, people with allergies are becoming more visible, no longer confined to foods thy carefully prepare themselves in their own kitchen. In addition, milder allergies are recognized and addressed than in previous generations; people who once may have had to just live with it are having an easier time avoiding foods that don’t agree with them. Moreover, it is believed that children are exposed to fewer pathogens than in years past, leading a bored immune system to latch on to innocuous foodstuffs.

One thing that’s important for people living with allergies is to look carefully at food labels. Even trace amounts of an allergen, such as residue on a piece of equipment, can cause a reaction, which is why packaged food sold in the United States is required to note on the product label when an item contains or may have come into contact with any of the Big Eight ingredients. Lactose intolerance and celiac disease are not, medically speaking, allergies, but people with thee conditions need to avoid cow’s milk and wheat respectively. While recent studies have cast doubt on the severity of gluten sensitivity other than celiac, celiac itself and wheat allergy are very real.

One of the most common tests to diagnose allergies is the skin prick test, in which food proteins are injected into the skin at a specific place. If the skin shows a reaction, this may indicate an allergy. While this test has extremely low instance of undersensitivity, it is often oversensitive. Trial elimination may be done as a followup or it may be the first test used. As the name suggests, suspected allergens are avoided for two weeks; if symptoms disappear, an allergy has been found.

Allergies Don’t Hibernate Over The Winter

Winter weather brings winter health problems, but wait before reaching for the cold medicine. Cold symptoms often mimic allergy symptoms, and it’s important to tell them apart so you don’t treat the wrong thing. The symptoms of the two can be very similar—runny nose, coughing, nose and chest congestion—but the causes are quite different.

Colds are viral infections. Specifically, the cold symptoms you experience are the body’s reaction to a viral infection. The congestion and blockages result from the immune system attacking any of hundreds of what are called rhinoviruses. Allergies, by contrast, are caused by a similar immune response but to normally harmless substances such as dust or pollen. While pollen is more common in spring and fall, dust is year-round, particularly for people with kids or pets.

That means, first of all, that colds are contagious and allergies are not. You can spread a cold, if you’re not careful—though you can avoid it by washing your hands regularly. Allergies are not contagious. While a tendency to develop allergies may be hereditary, the allergies themselves do not spread from person to person the way a cold or other viral illness does.

Another important difference is duration. A cold usually lasts less than two weeks—one that lingers longer than that is probably allergies. Colds come on gradually, a few days after infection, while allergy symptoms develop immediately upon exposure, meaning that allergies usually strike around the same time every year, with less variation than a cold. Anyone who talks about their "annual cold" probably has allergies, if not instead, possibly as well.

So how can you tell the which one is which? Aside from differences in onset and duration, the symptoms, though superficially similar, actually are different if you pay attention. Coughing, a sore throat, and yellow mucous generally mean a cold, and the achy feeling definitely does—that’s not an allergic reaction. On the other hand, itchiness in the eyes almost certainly is, and allergy mucous is clear. Lastly, while fever is rarely a cold symptom, it is never an allergic one.

Pets And Allergies

When the Obama family brought a dog into the White House in spring of 2009, they got a breed called a Portuguese water dog. This particular breed was chosen because of it’s coat, which is fleecy and sheds less hair than dogs generally do—an important consideration in light of Malia Obama’s allergies. Bo the dog was chosen in part to avoid triggering health problems in the President’s older daughter.

Later studies, however, found that so-called hypoallergenic breeds such as the Portuguese water dog are actually no safer, in regards to allergies, than other breeds. While some breeds shed less than others, shedding can also be controlled with grooming techniques. The allergy trigger isn’t really shed hair, according to pet experts; it’s dander, and while less shedding also means less dander, analysis of dust in homes with different dog breeds found no significant difference in the amount of allergens associated with different breeds of dog.

In fact, in homes with infants, dogs may actually prevent asthma and allergies from developing. The leading hypothesis for the cause of allergies is lack of exposure during childhood to harmless substances—such as pet dander—that nonetheless trip the immune system. That means having a pet in the home during childhood will help keep kids from allergic responses to irritants later in life. Now a study specifically confirms that pet dander protects against allergies. Infants raised with dogs that are regularly allowed outside have intestinal microflora that repel allergens and respiratory infection, and show less immune reaction to allergens.

In another study, dust found in homes with dogs served to protect against respiratory syncytial virus. RSV is common in infants, and while it is normally harmless, going away in less than two weeks, it can have a dangerous side. RSV is the most common cause of pneumonia in children under one year in the United States, and it’s particularly dangerous in children who already have conditions affecting the lungs, heart, or immune system. However, studies show that even in risky cases, having a dog in the house can help limit the severity and length of the infection.

Here, Kitty, Kitty!


Millions of people are allergic to cats. Rather than a regal darling, they see cats as the enemy, with exposure to a component of cat dander—typically a chemical called "Fel d 4," but there are four other types of allergens as well, and some people are sensitive to multiple allergens—causing an immune reaction. That means cats cause coughing, itchy and watery eyes, hives, nasal congestion, sneezing, chronic sore throat, itchy throat, or wheezing.

Now scientists are a step closer to understanding why. A British study looked at the specific immune response to cat dander and located the exact immune receptor that recognizes Fel d 4. The receptor is looking out for a bacterial toxin called lipopolysaccharide, and when Fel d 4 is accompanied by LPS, it triggers an allergic reaction. Using medications—developed for sepsis and other conditions—to suppress the activity of the receptor makes the allergy go away, but this is not necessarily a practical solution. Nonetheless, it gives researchers a potentially fruitful avenue of investigation.

Short of turning off part of your immune system, here are some ways you can deal with a cat allergy.

  • Keep your bedroom as a cat-free zone.
  • Brush your cat regularly to reduce the problem at the source.
  • Vacuum frequently and clean regularly to prevent dander from accumulating.
  • Use a HEPA filter to keep allergens down.
  • Wash your hands after touching your cat or anything your cat touches, such as toys and bedding.
  • Quality cat food with adequate fatty acids will keep your pet’s skin healthy and less allergenic.

If you’re a cat owner with a cat allergy, you’re not alone, One third of allergy sufferers find their love for their pets conquers the discomfort, though it does mean learning to live with it. Over-the-counter antihistamines, eye drops, and inhalers can provide relief, and an allergist may be able to help you find a longer-term solution.

Hay Fever And Your Asthma

As the weather gets warmer, the flowers bloom, the trees show their leaves—and the pollen comes out. For close to 40 million Americans, spring is time for seasonal allergies. For most people, seasonal allergies just mean coughing, sneezing watery eyes, and generally cold-like symptoms that last for months. For people with asthma, however, allergens in the air make it worse.

Allergies are similar to autoimmune disease, in that the immune system is defending the body against something that isn’t a thread—the body’s own organs in autoimmunity, and allergens such as tree pollen in allergies. In addition to tree pollen, inhaled allergens can include dust or mold, and these may be more prevalent in different weather conditions or seasons.

Not all allergic reactions lead to asthma symptoms, and not every allergy sufferer has asthma, but in people with both conditions—around half of all asthma sufferers are believed to also be allergic to inhaled particles—allergic reactions can lead into asthma attacks. That’s because the inflammation characteristic of asthma makes the bronchial tubes in the lungs particularly sensitive to irritation, which worsens the inflammation and makes breathing difficult. Other things can also trigger asthma, such as colds—which can occur in spring and summer as well as in colder months—smog, and cigarette smoke. Even cold air, particularly dusty air conditioning, can trigger an attack.

There are some treatments that are used for allergies and asthma alike. Medications to stop the immune system from responding to harmless allergens work by preventing the release of chemicals that signal the inflammation that leads to an asthma attack, meaning the allergens won’t cause a reaction or trigger asthma. A different sort of medication, called a leukotriene modifier, also modifies the immune response, in this case by acting directly on the chemical compounds in the body that are responsible for inflammation.