Patient Case: D.T.

University of Maryland - School of Medicine
Baltimore, Maryland

Instructor(s): Keogh, James P.; Gordon, Janie
Subject area: Health / Medicine
Department: Occupational and Environmental Medicine
Level: Undergraduate Medical
Learning objective: Develop Group Skills, Develop Individual Skills, Provide Information
Teaching style: Group Activity, In-class Activity

Please note that the copyright for this course project is retained by the instructor.



This case is presented to medical students at the University of Maryland School of Medicine. Developed by the University of Maryland's Occupational Health Project, this case focuses on occupational asthma. It teaches students to:
- Describe how exposures at home, in the community and at work influence health.
- Derive the elements of an occupational and environmental history.
- Develop an approach to assessing the work relatedness of an illness.
- Identify chemical exposures and find existing toxicological information.
- Learn how to gather more information from employers, co workers, and unions.
- Learn the capabilities and limitations of existing public health and regulatory agencies.
- Practice problem solving skills needed in caring for patients with environmental illnesses.


D.T. Patient History

D.T. is a 23 year old young man who was seen in the emergency room for a new onset of asthma.

The patient was in his usual state of health until yesterday when he developed wheezing while at work. He became so uncomfortable that he came home from work early and used an over-the-counter medicine for asthma. He got no relief and had difficulty sleeping last night because of cough and intermittent wheezing. He presents this morning with a persisting shortness of breath and audible wheezing.

There is no previous history of asthma, no history of allergies or atopy. He has been in generally good health except for a Colle's fracture of the wrist at age 17, which occurred while skateboarding.

He smokes one pack of cigarettes a day. He does not drink alcohol and drinks two cups of coffee a day. He denies any use of illicit drugs. He has never had symptoms of hay fever.

Script on Patient D.T.

You smoke one pack of cigarettes a day since age 16. You have never used illicit drugs. You do not use alcohol. You drink 2-3 cups of coffee a day while at work. You do not tend to drink coffee on the weekends.

Home Environment: You live in a row home in west Baltimore with your wife. She has been in good health. She works as a secretary in an insurance firm downtown. You have no pets and have had no recent repairs in your house. The ventilation system in the house is gas forced air. You have not had any problems with dampness or mold in the house that you are aware of. You are on city water and sewerage.

Community: You live in a residential neighborhood in west Baltimore. You are not aware of any problems with local sources of air pollution or other environmental exposure in the neighborhood. Occasionally, in the summertime, you have noted that the air in the neighborhood seems somewhat polluted and malodorous, but this never lasts more than about one day.

Work: You work as an electrician for a small electrical contracting firm. You have been doing this since age 21 and you usually work as the assistant to the owner of the company. You do a fair bit of commercial work and some industrial work.

Yesterday when you became ill you were working on a job involving wiring ventilating equipment in the roof of a factory building in Jessup, Maryland. The factory in question makes foam rubber (the T.W.B. Company). You had worked there only for about two hours when you became so short of breath that you had to leave work and go home. You were not using any protective clothing or respirator. You did note, however, that some of the employees were wearing rubber cartridge-type respirators while working around some of the chemical tanks in the plant. No one had suggested that you use respiratory protection or protective clothing.

You had worked in this plant once before, two weeks ago, on an earlier phase of this same project. At that time you were bringing in another power line from a breaker box at the side of the building and had to bring it up around some existing chemical equipment. This part of the job took most of two days. In the meantime, you have worked on a variety of small jobs for a number of commercial customers, mostly in the renovation of an office building in Fells Point. This has been essentially wiring around new construction and you are not aware of any unusual dust or chemicals on this job. There is no carpentry work or dry wall finishing going on while you were working.

Script for the Zap Electrical Company

Bob Zapp is the manager and owner. You were working with D.T. at the time that he got short of breath. You had to knock the job off for the day in order to drive him back to the shop where he could pick up his car. You have since completed the job on your own today and have not noticed any problems with your health.

You did note that some employees in the plant were wearing protective coveralls and using respirators. This has been the case on several previous occasions where you have done jobs for this company. You have never had difficulty with your breathing. You have never had it suggested to you that you should use protective equipment or a respirator. In as much as no activity was taking place on the conveyor belt you were working above, you did not think to ask about the possibility of any harmful exposures.

You would be happy to give the phone number of the plant engineer you have been doing the work for at T.W.B. Foam.

Script for G.S., the Plant Engineer at T.W.B. Foam

You are a polyurethane foam manufacturing plant and you produce a wide variety of polyurethane foam for customers in the carpet, automotive and consumer product industries. Your plant has an excellent safety record that you are quite proud of and you are constantly looking for improvements. You have, in fact, recently installed a new ventilating system in several areas of the plant in order to improve the safety of the plant and prevent any chemical exposures for employees.

You had not been asked about exposure to chemicals by the electrical contractor when he came. The safety for employees of contractors is really the responsibility of the contractor and not of your company.

Chemicals used at your plant include toluene-diisocyanate (TDI, which is the major constituent of polyurethane foam). You also add a variety of other sorts of catalysts and blowing agents in order to produce specific products for specific customers, but you are not at liberty to disclose them other than to say that they are generally non-toxic. You are aware that toluene-di-isocyanate, in some cases, cause asthma and sensitization. This usually occurs, in your opinion, in people who already have allergies and it merely reflects a predisposition on the part of the allergic individual. A very few workers at the plant have found that they are "allergic" to TDI and have had to switch to jobs where there is not much exposure.

If asked specifically, you may admit that the plant does not have a program of medical surveillance, the company has not done pulmonary function tests, and you really can't provide a reliable count of the number of workers who have been sensitized in the past. You may admit that some of them were laid off when no non-exposed work was available.

Script for Maryland OSHA re. the T.W.B. Foam Company

Your agency is well aware of the T.W.B. Foam Company. You have recently completed a month long inspection and investigation because of complaints of exposure to TDI and other chemicals.

The problems of the plant have included numerous employees with respiratory complaints. A survey by your nurse epidemiologist found 20% of individuals at the plant with complaints of shortness of breath. You have also identified seven individuals who have had to leave the plant because of asthma over the last five years. There has also been exposure to morpholine, which has created visual disturbances caused by mild corneal edema. Workers affected see "halos" around lights.

Only a few citations were issued because most of the exposures to TDI were well below the PEL. You did, however, strongly encourage them to improve the ventilation in the plant and you are delighted that they have done so. They have also instituted a program of protective clothing and respiratory protection. You are optimistic that the respiratory protection may not be needed in many parts of the plant once the changes in the ventilation in the building have been completed.

You should point out the limitations of MOSH in addressing a situation like D.T.'s and may wish to talk about the problems of exposures to contractors' employees in chemical plants.

Script for MDE for T.W.B. Foam Plant

You are aware of the T.W.B. Foam Plant because you received occupational disease reports from three different pulmonary physicians about three different patients who worked at this plant over the past several years and you have passed referrals on to MOSH. You would encourage inquiring physicians to contact MOSH as correcting the problem is their responsibility

You can ask if the patient in question works for T.W.B. . If he has to change jobs, as the previous asthma cases have, maybe he should be referred to the Division of Rehabilitation Services to talk about job placement or retraining.


This document was last modified on 06/14/2000 03:07:57 PM



This resource was acquired by CEEM (Consortium for Environmental Education in Medicine), a program of Second Nature, under the auspices of a NIEHS grant to gather and disseminate environmental health educational resources over the internet in order to help medical and allied health sciences faculty identify, locate and use resources for incorporating environment and health perspectives into their curricula. CEEM has authorized the use of these materials on this website for archival purposes. Please note that the copyright for this material is retained by the instructor and/or contributing institution.