Some laboratories offer a blood test that measures immunoglobulin G (IgG) antibodies to allergenic sub-stances. IgG has never been demonstrated to be an important cause of allergic reactions; in fact, IgG may play a protective role in modulating the severity of allergic responses. IgG antibody tests have not been shown to accurately predict the occurrence [...]

An alternative to allergy skin testing is blood testing, in which a small sample of a patient’s blood is tested for the presence of IgE antibodies. In the past, the testing assay was based upon a radiolabeled technology called the radioimmunosorbent test (RAST). More recently, laboratories have devised a new technique referred to as the [...]

To determine what a patient is allergic to, a physician will need to perform an allergy test. Allergy tests assess whether a patient has IgE antibodies to a specific allergenic substance. The most commonly performed allergy test is the allergy  prick/puncture skin test, in which a small amount of allergen solution is placed on the [...]

Chronic nasal complaints developing later in life are usually not allergic in origin. The most likely causes of new-onset rhinitis in patients older than 60 years of age includes nonallergic rhinitis, anatomic obstruction (such as a deviated septum or concha bullosa), drug-induced rhinitis (topical decongestants and some blood pressure medications), and rhinitis associated with systemic [...]

Infants younger than 1 year of age frequently have signs of nasal blockage, most often because of thick secretions that are stuck in their nose. Other symptoms, such as sneezing or ocular symptoms, are much less common in very young children. This problem has been referred to as “rhinitis of infancy,” which is almost universally [...]

I was told that I have a deviated septum and that this makes my allergies worse. Do I need to have it surgically repaired? The nasal septum is the small cartilaginous structure that divides the nose into halves. Approximately one-third of people have deviation of the septum toward one side of the nose or the [...]

Alcoholic beverages, regardless of type, dilate blood vessels throughout the body, including the nose, and frequently cause an increase in nasal congestion. In addition, alcohol is dehydrating and may lead to a thickening of nasal secretions. It does not generally lead to other symptoms, such as sneezing, itching, or nasal discharge. The effect of alcohol [...]

I’ve been using Afrin nasal spray daily for the past 6 months to treat my stuffy nose. Why do my symptoms seem to be getting worse? Frequently, patients with nasal congestion caused by an acute upper respiratory infection or nasal allergies will treat themselves with an over-the-counter nasal decon-gestant spray such as Neo-Synephrine (phenylephrine) or [...]

It has been a widely held belief that drinking milk or eat-ing dairy-containing foods causes an increase in nasal mucus production. However, there is no scientific evi-dence that daily consumption of milk has a chronic effect on nasal mucus production. Milk can act as an allergen in children (usually younger than 5 years) and occasionally [...]

There is a large group of people, probably constituting 50% of patients with chronic nasal symptoms, who develop a watery nasal discharge and/or stuffiness when they are around certain nonallergenic nasal triggers. This nasal disorder is called  nonallergic rhinitis,and the triggers that are most commonly reported include cold air, airborne irritants (e.g., perfume, paint fumes), [...]

I work in an office building with sealed windows, and my nasal symptoms seem worse while I’m there. Could the building be responsible? Many patients note that their symptoms mainly occur, or worsen, while they are at work. This condition is referred to as occupational rhinitis. The most common causes of work-related symptoms are airborne [...]

The most important allergens that cause allergic rhinitis are airborne substances. These airborne allergens can be divided into those that are present only seasonally versus those that are present year-round (also called “perennial”). Seasonal allergens are generally present in the outdoor environment and include tree, grass, and weed pollens as well as outdoor molds. In [...]

Symptoms of allergies and colds can be quite similar, but there are some differences that will help distinguish them (see Table 3). With regard to the types of symptoms, both allergies and colds cause symptoms of sneezing, congestion, and runny nose. However, colds are more likely to begin with fever and sore throat before the [...]

Patients with seasonal nasal allergies, also known as seasonal allergic rhinitis or seasonal hay fever, often have intermittent nasal symptoms that may become acutely worse while the patient is outside of the house, particularly if it is windy. Symptoms usually consist of some combination of sneezing, itching of the nose, nasal discharge, and congestion. Sneezing [...]

Usually, eczema (atopic dermatitis) develops in the creases of the arms and behind the knees in the first year of life and signifies that a child will be an allergic individual. Approximately half of children with atopic dermatitis will go on to develop allergic rhinitis and/or asthma in the next 5 to 10 years. Of [...]

There is a strong genetic component in determining which individuals will develop allergy. If one parent has an allergic disease, including asthma, rhinitis, atopic der-matitis, or food allergy, there is an approximate 40% chance that the child will have some form of allergy; with both parents having an allergic disease, the risk rises to 60%. [...]

These alarming increases are not completely understood. However, one popular explanation has been labeled the hygiene hypothesis. This theory stipulates that all humans are born with an allergic predilection. As grow-ing infants encounter new environmental challenges, such as viruses and bacteria, their immune systems shift away from the allergic profile toward one that is capable [...]

Over the past 2 decades, a significant portion of the world, particularly the United States, western and north-ern Europe, Canada, Australia, and New Zealand, has witnessed a substantial increase in allergic diseases. Approximately 2 decades ago, 3% of the American pop-ulation had asthma; today the prevalence is closer to 7%. Similarly, during the same time [...]

The primary allergic diseases include allergic asthma,allergic rhinitis, atopic dermatitis, anaphylaxis, and food hypersensitivities . Asthma is a disease of the lungs in which the bronchial mucous membrane is chronically irritated and inflamed. This inflammation makes the airways more hyperreac-tive to a variety of provocative stimuli, including allergens, cold air, exercise, and viral infections, leading [...]

The word allergy refers to a reaction to an environmen-tal substance, either by breathing it, eating it, or having contact with the skin. The most common mechanism by which an environmental substance causes this kind of reaction involves antibodies, which are proteins formed by the immune system. The normal function of anti-bodies is to protect [...]