Related Experiment Video
Updated: Jun 28, 2026

A Component-resolved Diagnostic Approach for a Study on Grass Pollen Allergens in Chinese Southerners with Allergic Rhinitis and/or Asthma
Published on: June 4, 2017
A clinical study of Japanese cedar (Cryptomeria japonica) pollen-induced asthma
Yuji Maeda1, Kazuo Akiyama, Takao Shida
1Clinical Center of National Hospital Organization Sagamihara Hospital, Kanagawa, Japan. y-maeda@sagamihara-hosp.gr.jp
Background:
Grass and birch pollens are known to induce asthma. However there are few reports about other pollen-induced asthma. Japanese cedar is the most common allergen in rhinitis in Japan but is controversial on whether it can provoke asthma.
Methods:
To clarify Japanese cedar pollen-induced asthma, we studied adult patients who were sensitized only to the Japanese cedar (CAP-RAST > = 2) and had symptoms of asthma during the cedar season. We defined cedar asthma as a patient who satisfied the 2 criteria mentioned above.
Results:
We found 6 adult asthma patients who fulfilled the two criteria. Five patients suffered from cedar pollinosis in addition to asthma, and 1 patient had no pollinosis. The cedar pollinosis preceded asthma in 3 cases and occurred at almost the same time in the other 2 cases. Pulmonary function was normal in these cases (FEV 1%, mean +/- SD, 76.5 +/- 10%), with a high threshold value in the non-specific airway hypersensitivity test (Ach-PC20, 2,696 to 20,000 microg/ml, 9294 +/- 2) and low total IgE (101 +/- 86 IU/ml). In the allergen provocation test, 3 subjects showed both an immediate and late asthmatic reaction.
Conclusions:
We concluded that Japanese cedar pollen could provoke not only pollinosis but also asthma in adults.
Related Concept Videos
Asthma III: Clinical Manifestations
Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Asthma-I: Introduction
Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
Asthma-III: Symptoms and Complications
Classification of Asthma
Asthma-IV: Diagnostic and Management
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
