Nasal Discomfort Can Be Caused By Irritants on the Job

Occupational rhinitis (OR) is the name given to inflammation of the membranes lining the nose caused by exposure to job-related irritants or substances inducing allergy. It is characterized by sneezing, congestion, postnasal drainage and related symptoms. In one type of OR, allergic occupational rhinitis, the time between exposure to irritants and development of symptoms may range from two months to 18 years. However, irritant or non-allergenic OR may occur immediately after a high level of exposure to job-related irritants.

Up to 15% of people suffer from occupational rhinitis and this number may be an underestimate because workers may not report symptoms for fear of repercussions at work. OR may be further underestimated because the symptoms don't always occur at work and may be difficult to connect to the job. Workers at particular risk of developing OR are those with a personal or family history of allergic diseases. A study of laboratory workers exposed to rats found that 45% of atopic patients -- those with positive skin tests for mites and grass allergies -- became allergic to rats within their first year on the job, compared to only 3% of non-atopic patients. Smoking also may be a risk factor for OR caused by certain chemicals.

High-Risk Jobs
High-risk occupations include those that involve frequent exposure to chemicals, animals, flour and latex. These include farmers, pharmaceutical workers, carpenters or wood workers, workers exposed to epoxy resins, health care workers, and food processing industry workers. The food industry accounts for the largest proportion of OR cases. Up to 70 types of wood dusts may provoke occupational disease by contact or inhalation. As many as 15% of health care workers may be sensitized to latex. Latex-induced OR may persist even after removal from the latex-exposure environment.

The concentration of offending agents and the duration of exposure affect the risk of developing OR. Other workplace factors include use of proper industrial hygiene methods (such as gloves and masks, and ventilation); accidents or spills; and exposure to ozone, pollution, or cold air. Snorting illegal drugs may also be a factor. More than 200 potentially hazardous chemicals in the workplace have been associated with OR or occupational asthma, a related condition.

Chemical properties of a substance may make it more likely to cause rhinitis symptoms. Formaldehyde, for example, causes rhinitis because it is a highly water-soluble gaseous pollutant, making it easily retainable in the nasal membranes. It can be found in particle board, plywood, adhesives, some cosmetics, floor coverings and the backing on carpets.

Other Causes
Non-allergic causes of OR include many substances, such as sulfur dioxide (from burning coal or oil), fluorine, paint fumes, flower fragrance, pesticides, cleaning agents, toluene and perfumes. Non-allergic OR caused by corrosive chemical gases such as ammonia, chlorine, acids and vinyl chloride can cause significant inflammation and permanent damage. Some non-allergic forms of OR may occur at first exposure to a substance, whereas allergic OR may occur only after weeks or years of exposure and symptoms may not be present at the job site.

Sick building syndrome (SBS) is not the same as OR. SBS is mucous membrane irritation caused by inadequate air handling equipment in new, energy-efficient office buildings. People with this condition experience symptoms only in the affected building. Chemicals that may cause SBS symptoms include carbonless copy paper, photocopier fumes, cleaning agents, and solvents.

Treatment
A complete medical history, including discussion of potential job-related factors, plus a physical exam of not just the nose and sinuses, but eyes, skin, mouth and lungs may be helpful in diagnosing OR. Prevention is the best form of treatment; avoidance is the next choice, followed by environmental controls such as protective clothing and improved ventilation. Medication is most effective for allergic OR and includes antihistamines and decongestants.

Jordan N. Fink, MD
Medical College of Wisconsin Professor of Pediatrics and Medicine

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.