Respiratory tract reactions to western red cedar

Area of Science:

• Allergy and Immunology
• Occupational Health
• Respiratory Medicine

Background:

• Western red cedar (Thuja plicata) is a known cause of occupational asthma, though infrequently reported in the UK.
• Two cases of UK workers developing asthma and rhinitis from occupational exposure to western red cedar are presented.

Observation:

• Patients experienced symptoms following exposure to western red cedar.
• Bronchial challenge tests were performed to assess asthmatic responses.
• Anterior rhinometry was used to monitor nasal responses in one patient.

Findings:

• Both patients exhibited late asthmatic responses after bronchial challenge with western red cedar.
• The study describes the challenge technique and compares responses to different wood dusts and extracts.
• A late nasal reaction, mirroring the bronchial response timeline, was observed in one patient via rhinometry.

Implications:

• This study highlights the potential for western red cedar to cause significant respiratory and nasal allergic reactions in occupational settings.
• The findings underscore the importance of recognizing and diagnosing occupational asthma and rhinitis related to wood dust exposure.
• Effective diagnostic techniques, including bronchial and nasal challenge, are crucial for identifying causative agents and managing patient care.