allergies - general information

Your eyes are watery, your nose is itchy and runny, and you've got a throbbing headache from the pressure in your sinuses.

You're suffering from allergic rhinitis, and you're not alone. As many as 50 million people of all ages regularly suffer those same uncomfortable symptoms. They're caused by irritants called allergens-normally harmless substances that trigger overreactions in the immune systems of susceptible people.

Perennial allergies can occur year-round because they are caused by allergens in your living environment-often in your home. Allergies can also be caused by exposure to irritants such as paint fumes and cigarette smoke.

Pollens and molds are the main causes of seasonal allergic rhinitis (often called hay fever). In the United States, ragweed pollen prompts most seasonal symptoms. Grass and tree pollens are responsible for the rest.

Food allergies - most common allergies

Food allergies are among the most common allergies observed among the general population. Recent evidence presented during the Scientific Poster Session at the annual meeting of the American Academy of Allergy, Asthma, and Immunology confirms that there is no lack of food allergies being observed in clinical practices throughout the world.

More than a dozen presentations described allergic reactions to a wide range of common and exotic foods. These manifested in various ways, from mild rashes to severe and immediate anaphylactic reactions. There were reports of reactions to common foods, including:

• Kidney and white beans found in chili

• Beef and venison

• Coconut and walnut

• Mulberry fruit

• Corn, and

• Mustard.

Rare food allergies were reported by two patients enrolled in a study on the use of shiitake mushrooms (the second most commonly eaten mushroom in the world) for lowering cholesterol; they developed eosinophilia that was associated with other immunologic changes.

Rambutan (a malay word meaning "hair") is a fruit found in Thailand that can cause an acute allergic reaction.

The Naval Medical Center reported on an American sailor who developed hives and throat swelling while on duty in Thailand after ingesting a fruit called rambutan (the Malay word for "hair") (see photo). Interestingly, he had never eaten the fruit before and had probably cross-reacted with some other pollen.

One patient had used a capsaicin-containing (0.075%) analgesic cream for 4 years with no problems. However, during that time she did notice facial edema and other allergic signs whenever she ate peppers (Capsicum). It is likely that the repeated use of the cream sensitized her to the capsaicin that is naturally found in hot peppers.

Although these cases represent somewhat unique reactions to common foods, it should be remembered that we are all at risk for sensitization to some foods. Allergic reactions to foods may be more common than we think. source:AAAAI

Do Allergy Shots Help Asthma?

Because allergens trigger bronchoconstriction in more than half of asthmatics, investigators at Johns Hopkins School of Medicine studied ragweed pollen immunotherapy in asthmatics with symptoms during ragweed pollination season. Compared with placebo, purified ragweed pollen immunotherapy produced a small but statistically significant increase in peak expiratory flow and reduced the use of asthma medications during the first year. However, benefits were not apparent during the second year of therapy. Because asthmatics usually respond to multiple allergens (including house dust mite feces, which are generally not responsive to allergy shots), immunotherapy for asthma appears to be of limited value.

Sulfites, Allergies, and Asthma

Sulfur-based preservatives -- sulfites -- have been used for centuries to inhibit the oxidation of light-colored fruits and vegetables (the "browning" of apples or potatoes), prevent melanosis on shrimp and lobster, block bacterial growth in fermenting wine, condition dough, bleach food starches, and maintain the stability and potency of certain medications (see side bar). Unfortunately, many people, including approximately 5% of asthmatics, are allergic or sensitive to sulfites. According to a report in the FDA Consumer, the FDA currently prohibits the use of sulfites for maintaining the color and crispness of fruits and vegetables meant to be eaten raw; it also requires manufacturers to label products (including packaged, bottled, and bulk foods) that contain sulfiting agents. However, current FDA regulations do not apply to restaurants.

Sulfites in a concentration lower than 10 parts per million can trigger an attack. The most rapid reactions occur when sulfites are sprayed on food or are used in a beverage, but the most severe reactions occur when sulfites are in the food itself. Asthmatics are probably sensitive, not allergic, to sulfites; exposure occurs when sulfite fumes are inhaled from treated foods. Bronchoconstriction can be severe enough to completely block breathing, causing hypoxemia with brain damage, heart or other organ damage, or fatal arrhythmia. Patients with asthma who are dependent on oral corticosteroids are more apt to be sulfite sensitive, and they have an increased risk of severe reactions. However, in some cases, the very first asthma attack is a sulfite reaction.

Sulfite sensitivity can be difficult to diagnose. A sulfite challenge may be appropriate for patients who react adversely to certain foods. For example, if the suspect food causes hives, a sulfite skin-prick test may be performed. Patients with a positive skin test are more likely to be allergic, rather than sensitive, to the sulfite; they usually are not asthmatic and are at greater risk for anaphylaxis. According to the FDA Consumer, people who have had a serious sulfite reaction should carry an antihistamine and a self-injectable epinephrine when they eat out, and asthmatics should use a bronchodilator. Sulfite-sensitive people should also read food labels, ask store managers or waiters to check labels on bulk foods, avoid foods known to contain sulfites in other forms-and never just assume a food is safe to eat.
source:Medical Sciences Bulletin

Taking cough medicine - treating coughs

As part of simple self-care for your cough, take an over-the-counter (OTC) cough medicine. These medicines work to make your cough more productive or to quiet a disruptive cough. Types include:

* Expectorants cough medicine— The name expectorant comes from the verb "expectorate," meaning "to spit." These cough medicines contain guaifenesin, an ingredient that works to loosen mucus in your airways. As a result, expectorants can help clear your airways of irritants. Taking a cough medicine, drinking plenty of water and breathing moist air offers maximum loosening of mucus.

* Suppressants cough medicine— To temporarily reduce the frequency of your cough, take a cough suppressant. These medications, also called antitussives (from the Latin word for cough), act directly on the cough center in your brain. Some antitussives contain a narcotic such as codeine. Nonnarcotic antitussives, such as dextromethorphan and diphenhydramine, are available in nonprescription cough medicines. These ingredients help relieve coughing without the risk of side effects associated with narcotics. If your cough brings up mucus, it's best not to suppress it. But if your cough is frequent and produces small amounts of mucus, consider using a combination medicine containing both an expectorant and a suppressant.

* Expectorants plus suppressants cough medicine — Some cough medicines contain an expectorant plus a cough suppressant. The expectorant helps loosen mucus while the cough suppressant reduces the frequency of your cough. In combination, these ingredients can make your cough more productive while making you more comfortable.

how can you control coughs? - treating coughs

# Drink extra liquids — Sometimes secretions in your lungs become thick and sticky, making them difficult to remove by coughing. A cough that doesn't bring up mucus is nonproductive (dry). Drinking plenty of liquids, especially water, helps thin and loosen mucus to make your cough more productive. By bringing up mucus, a productive cough helps clear your airways of irritants. Beverages such as juices and hot tea can also soothe and lubricate your throat.

# Breathe moist air — Taking a shower or using a humidifier or vaporizer also helps loosen mucus.

# Soothe your throat — Sucking on hard candy or cough drops, or drinking tea sweetened with honey may help prevent coughing if your throat is dry or sore.

# Try not to cough — Frequent dry coughing can worsen irritated airways. Try to cough as seldom and gently as possible. Taking frequent sips of liquids may help stifle the cough cycle.

Causes of cough - treating coughs

Here are typical reasons for a cough:

* Infection — Cold and flu (influenza) viruses are the most common causes of cough. Coughs from colds typically develop when excessive amounts of mucus irritate your airways.

* Asthma — Various forms of asthma and asthma-like conditions affect up to one in 10 people. Coughing is a common symptom during the night, after exercise or when exposed to irritants.

* Post-nasal drip — An overproduction of mucus can occur with some allergies and sinusitis (inflamed mucous membranes within sinuses). The slow trickling of mucus from the back of your nose down into your throat causes irritation.

* Environment — Irritants include smog, dust, home aerosol sprays, cigarette smoke and cold or dry air. Cigarette smoke irritates the airways of both smokers and nonsmokers. If you smoke, nicotine paralyzes the movement of tiny hairlike projections lining your airways called cilia. When cilia can't help clear excess mucus, the sticky secretions build up and cause coughing.

* Medications — Coughing can be a side effect of inhaled medications, such as corticosteroids. Coughing can also occur with use of some beta blockers and angiotensin-converting enzyme (ACE) inhibitors prescribed for high blood pressure or heart disease.

* Unexplained cough — Sometimes there's no medical explanation for a cough. Some people have a persistent cough after an infection resolves. Others may cough to release tension, gain attention or express anger. Whatever the reason, continual coughing can irritate your throat and set up an exhausting cycle.