Clinical Cases

A Case of Asthma in a Baker

Case Editor - Judd Flesch

Reviewed By Allergy, Immunology & Inflammation Assembly

Submitted by

Navjeet Uppal, MD

Division of Respiratory Medicine

Department of Medicine

University of Toronto

Toronto

Susan M Tarlo MB BS

Division of Respiratory Medicine

Department of Medicine

University of Toronto

Toronto

Submit your comments to the author(s).

History

A 44 year old woman, currently working in a bakery, presents with a 1 year history of asthma and allergic rhinitis symptoms, including episodic cough, wheeze, shortness of breath and chest tightness with itchy red watery eyes and a stuffy, runny, itchy nose. These symptoms become worse within 1-2 hours of starting work each day, and worsen throughout the work week. She especially finds red bran to worsen her symptoms almost immediately on exposure. She notices an improvement within 1-2 hours outside of being at her workplace. She has been working in the bakery for 13 years, and for the last 10 years has been a "pre-scaler", weighing components, while wearing a paper mask. The line that she has worked on for the last 2 years is dustier than other areas.

Her past medical history is significant for seasonal allergic rhinitis in the summer months since childhood. She is a lifelong non-smoker. Her family history is significant for asthma in her mother and brother.  She currently uses an inhaled steroid-long acting bronchodilator (ICS-LABA) daily, and inhaled short-acting bronchodilator (SABA) as needed, generally up to 4 times a day at work with relief.

Physical Exam

Her physical examination is normal.

Lab

Her chest x-ray is also normal.  Spirometry testing shows FEV1/FVC 0.62 (within 24 hours of work), FEV1 1.9L (60% predicted), and post-bronchodilator, the FEV1 increases to 2.2L (300cc, 16%). One year earlier, after 2 months off work, her FEV1 was 2.3L. Skin prick testing was positive to grass (3+), a slurry of workplace flour (3+), wheat germ (3+), and red bran (2+). Her home peak expiratory flow readings ranged between 270 and 340, with lower readings on workdays (figure 1).

Diagnosis and Management

A diagnosis of occupational asthma from wheat (including wheat germ and bran) was made. She was transferred to a muffin packing area where flour exposure was minimal, if any, and was followed with further peak flow monitoring and spirometry: she has since remained well with no symptoms and requiring no medications.

Spirometry testing shows FEV1/FVC 0.62 (within 24 hours of work), FEV1 1.9L (60% predicted), and post-bronchodilator, the FEV1 increases to 2.2L (300cc, 16%). One year earlier, after 2 months off work, her FEV1 was 2.3L. Skin prick testing was positive to grass (3+), a slurry of workplace flour (3+), wheat germ (3+), and red bran (2+). Her home peak expiratory flow readings ranged between 270 and 340, with lower readings on workdays (figure 1).

Figures


Figure 1: Peak expiratory flow rates during days on and off work in the main bakery

Question 1

In patients with a history of possible occupational asthma, which of the following is important to establish a diagnosis?


References

  1. Baatjies R, Meijster T, Heederik D, Sander I, Jeebhay MF. Effectiveness of interventions to reduce flour dust exposures in supermarket bakeries in South Africa. Occup Environ Med 2014;71:811-8.
  2. Baatjies R, Meijster T, Heederik D, Jeebhay MF. Exposure-response relationships for inhalant wheat allergen exposure and asthma. Occup Environ Med 2015;72:200–207.
  3. Gautrin D, Ghezzo H, Infante-Rivard C, Malo JL. Incidence and determinants of IgE-mediated sensitization in apprentices: a prospective study. Am J Respir Crit Care Med 2000;162:1222-8.
  4. Heederik D, Henneberger PK, Redlich CA. Primary prevention: exposure reduction, skin exposure and respiratory protection. Eur Respir Rev 2012;21:112-24.
  5. Malo JL, Chan-Yeung M. Agents causing occupational asthma. J Allergy Clin Immunol 2009;123(3):545-50.
  6. Tarlo SM, Balmes J, Balkissoon R, et al. Diagnosis and management of work-related asthma: American College Of Chest Physicians Consensus Statement. Chest 2008; 134:Suppl:1S-41S. [Erratum, Chest 2008; 134:892.]
  7. Tarlo SM, Lemiere C. Occupational asthma. NEJM 2014;370(7):640-9.
  8. Tarlo SM, Liss GM. Prevention of occupational asthma. Curr Allergy Asthma Rep 2010;10:278-86.