Allergic Rhinitis must is the most obvious environmental disease. Hay fever is the prototype of Type I allergy. The mechanism was thought to be a straight forward histamine-mediated response to inhaled antigen. Drugs that block histamine are effective in relieving hay fever symptoms. The early, immediate response is sneezing and anterior nasal discharge, often profuse.

Hay Fever and Allergy Ads

Hay fever is the most clear-cut case of allergy. Ads for antihistamines proclaim the simplest mechanism of allergy:

• an inhaled allergen (antigen), grass pollen, meets antibody-coated mast cells waiting in the mucosal surface of the nose

• a typical hay fever attack with sneezing, itching, and nose congestion results.

A similar reaction in the throat produces soreness, mucus flow, swelling, and difficulty in swallowing and breathing (pharyngitis, laryngitis). A similar reaction in the lungs produces cough, mucus obstruction to airflow, and asthmatic wheezing (bronchitis, asthmatic bronchitis).

The clinical practice of "Allergy" as a specialty has tended to restrict the definition of allergy to one pattern of immune reactivity described as "Atopy" by Coca and Cooke in 1925. The term "atopy" simply meant "strange disease". 

Allergists noticed connections among the "'strange diseases" including hay fever (seasonal allergic rhinitis and conjunctivitis), asthma and eczema - the three members of the atopic group. Study of atopic hypersensitivity revealed a common immune mechanism which further confirmed the allegiance of many allergists to atopy, with the exclusion of other allergic diseases from their field of interest. It was found that a single antibody species, IgE or "reaginic antibody", was responsible for some of the typical manifestations of atopy.  An inherited tendency to make excessive amounts of IgE antibody is one characteristic of atopic individuals. Flash maps

• IgE reactions tend to be immediate, causing obvious allergic reactions.

• IgE-mediated reactions tend to correlate with positive skin and/or RAST tests.

The drug, cromolyn, blocks mast cell degranulation and can prevent the whole allergic cascade from developing. Antihistamines, prostaglandin  and leukotriene inhibitors knock out a fraction of the subsequent responses. Once underway, corticosteroids are the only drugs that block the late and delayed phase responses. The Type 1 allergy mechanism may activate delayed cell-mediated (lymphocytic) immune responses which extend the disease from hours to days. Repeated antigenic stimulus then prolongs tissue inflammatory events toward chronic disease.

Nose Reactions and Skin Tests

A convenient correlation between nose-reactive IgE and skin-reactive IgE was discovered. By introducing tiny amounts of suspected antigens into the skin, a local wheal and flare reaction, like a mosquito bite, is produced if reactive IgE is present on skin mast cells. The association of hay fever, asthma, and skin tests with allergy practice was further confirmed by the relative success of "allergy shots". These shots came to characterize the allergist's office; other aspects of allergy practice often were neglected.

Allergy shots are immunological treatments. The immune response to any reactive substance can be modified by giving repeated challenges of the reactive substances. Allergy shots for hay fever start with a serum containing the pollen antigens which caused positive skin responses. The antigens are administered in increasing concentrations by regular injections under the skin. It remains unclear how the shots work.

One response to the injected antigen is the production of a second antibody population of the IgG class. These IgG antibodies are thought to compete with IgE antibodies, "blocking" the allergic response. It is also possible that the antigen injections stimulate suppressor T-cells or inhibit helper T-cells and reduce production of IgE.

Allergy shots have limited therapeutic application. The hay fever sufferer and some asthmatics with specific inhalant reactions to grass pollens do well with desensitization. Immunotherapy also protects patients who have had anaphylactic reactions to bee and wasp stings. Patients with complex reactivity, food reactions, and drug reactions do not do well with allergy shots, and the shots are not usually recommended. It is our policy to avoid allergy shots in patients who have food allergy and other forms of delayed immune responses.

We are indebted to Richard Trevino, MD, President, American Academy of Otolaryngic Allergy for this summary of the health effects indoor air pollution with emphasis on the upper respiratory tract.

The nose is very efficient at trapping  inhaled pollutants and it concentrates these chemicals as part of the process of cleaning inspired air. The trapped, concentrated pollutants can cause local tissue swelling and chronic obstruction of the sinuses, leading to chronic infectious processes and then to chronic purulent sinusitis. In addition, some chemicals are absorbed through the nasal mucosa and into the systemic circulation, causing the body to attempt detoxification of the chemicals by oxidation, reduction, conjugation, and/or degradation.

During the detoxification process, pollutants may become even more toxic than they were in their unoxidized forms. These pollutants may produce subtle, but important changes in the body, such as reduced T-suppressor cell activity. This suppression leads to a relative increase in the activity of B-helper cells, which then produce an excess of immunoglobulins, and therefore an increase in allergic phenomena.

These problems can be lessened by avoiding chemicals and air pollution through use of good ventilation systems and protective masks in the workplace. When these precautions are not possible, some patients should seek work in different areas or change jobs.

A second preventive strategy is to increase dietary intake of certain substances. Specifically recommended is dietary supplementation with antioxidants (Vitamins A,B,C, and E; and betacarotene), as well as trace minerals (i.e., selenium, manganese, magnesium and others), and amino acids. The ultimate goal, however, is to decrease the concentration and amount of pollutants being produced through pollution prevention.

Examples of Air Pollutants

"Environmental tobacco smoke (ETS) is at the top of the list of carcinogenic environmental toxins of concern to physicians. A decrease in indoor air quality if often the result of poor ventilation resulting from more efficient construction practices in sealing homes and office buildings from the outdoor environment. Reduced ventilation has resulted in complaints related to the "Sick Building Syndrome" (SBS), which is characterized by symptoms such as headache, fatigue, malaise, mental confusion, eye and throat irritation, and coughing and wheezing. (see multiple chemical sensitivity )

Indoor air pollution can be the result of occupational exposures, hobby or recreational chemicals, carpets and furniture or indolent materials present in the air because of poor building ventilation or contamination. While all of these are potentially harmful, the occupational exposures may be the most risky. At work, volatile organics such as gasoline, cleaning solutions and solvents, and other organic chemicals can be health hazards. Chronic low-dose exposures may be additive, especially with respect to mucous membrane irritation, but no solid scientific studies on this matter are available at this time. (See indoor air) Buy cheap Lapidary Cabochons

Examples of concern about occupational hazards include the awareness that an upper respiratory tract carcinogen is present in the strong acid process for producing ethanol and isopropanol and is site-specific for the larynx. It has also been determined that the odds ratio for nasal and sinus carcinoma in metal workers and foundry workers ranges from 3 to 6 with adenocarcinoma being the most common cell type of tumor. Working in the wood, leather and textile industries also carries an increased risk as does exposure to dust and fumes in the farming and breeding industries. Among men, the risk of adenocarcinoma is particularly high for cabinet makers, carpenters and joiners as well as woodworking machine operators. Cabinet makers, carpenters and joiners also have a significantly increased odds ratio for other cancers. Simply being exposed chronically to wood smoke carries an increased risk because of the known carcinogenic and ciliary-toxic effects of the particulate matter being inhaled. The odds ratio for developing a cancer is 5.3 in males exposed to high levels of wood dust and formaldehyde and is increased in workers exposed to glues and adhesives.

Formaldehyde is a volatile organic chemical which is water-soluble. It is found in resins, plywood and particle board, insulation and embalming fluid and is used in many manufacturing processes as well as being found in cigarette smoke. It is highly irritating to the nasal mucosa and can cause a hypersensitivity reaction with repeated exposure. Animal studies have shown carcinogenicity in dose-related occurrences of carcinoma of the nasal passages. In humans, there is the suggestion of an increased odds ratio for both carcinoma and poorly reversible mucosal disease in exposed individuals. In mortuary science students, a dose-response relationship was observed between cumulative exposure to formaldehyde and increased abnormal cellular markers in the oral mucosa.

In some healthcare facilities, localized air pollution is also of concern. Volatile anesthetic gases are occasionally vented into the operating room, exposing all who are present to their low-dose effects. Anesthetic gases are normally vented to the atmosphere where they can potentially participate in the reduction of the ozone layer and result in greater human, plant and animal exposure to ionizing solar radiation. Concern has also been raised regarding laser plume smoke, especially for laryngeal papillomata where viral DNA may be inhaled by the operator and others in the room.

Acetone, cleaning solutions, chemotherapeutic agents and other chemicals may pose some occupational risk to the healthcare workers in acute exposures.

Because the upper aerodigestive tract represents the most common route of human ingestion or airborne chemical pollutants and toxicants, adverse effects on the mucous membranes seem plausible. In many situations, such as in the metal and woodworking industries, carcinogenesis can occur. Tobacco smoking over a critical time period and at a critical dose level can clearly cause cancer over the entire upper aerodigestive tract. Occupational exposures to solvents, organic pesticides, formaldehyde and many other pollutants may cause tumors as well as chronic mucosal irritation and may alter the normal physiology of the nasal cavity, paranasal sinuses and larynx.