Â鶹AV

Nasal allergies can be categorized into perennial and seasonal types. Perennial allergies manifest symptoms throughout the year and are caused by indoor house dust, mites, and mold. Seasonal allergies are represented by Japanese cedar and cypress pollen allergies (pollinosis). It is now considered a national affliction. Grass pollens like sweet vernal grass and ragweed pollen allergies are also well-known.

Japanese cedar pollens, which trigger cedar pollinosis, come from Cryptomeria japonica, an evergreen conifer tree endemic to Japan. The Japanese cedar has been present in Japan for approximately two million years, far before the origins of the Japanese people. However, much of the cedar forests in Honshu nowadays are artificial forests resulting from post-war afforestation policies. Statistics show that 45% of these artificial forests consist of Japanese cedar, and 21% of cypress trees, contributing significantly to the increase in cedar and cypress pollinosis allergy cases.

The first report of Japanese cedar pollinosis in Japan was made by Dr. Yozo Saito, an otolaryngologist, in the 1960s in the area around Nikko in Tochigi Prefecture. Since then, the number of patients has continued to rise. National surveys indicate that the total number of nasal allergy patients in Japan is estimated to be at least 18 to 23 million people. A nationwide epidemiological survey conducted in 2007 reported a 4.8% increase in patients with perennial allergic rhinitis and a 10.3% increase in cedar pollen allergy cases over the preceding decade.

The symptoms of nasal allergies naturally occur inside the nasal cavity and are characterized by three main features: "sneezing," "runny nose," and "nasal congestion."
On the other hand, the human nose serves vital functions, such as warming and humidifying inhaled air, removing foreign particles, and regulating nasal airflow through periodic swelling and contraction of the nasal mucosa (the nasal cycle). From this perspective, "moderate" nasal mucus secretion (rhinorrhea), the perception of nasal airflow, and resistance are the symptoms present in all healthy individuals. Conversely, the three main symptoms of nasal allergies can be interpreted as follows: sneezing as disruption in the foreign particle removal mechanism, excessive nasal mucus as disruption in the humidification mechanism, and nasal congestion as a combination of nasal cycle disruption and manifested eosinophilic inflammation.

The disturbances in these nasal functions caused by nasal allergies significantly impact human productivity and lead to a decline in quality of life (QOL). However, there is often a discrepancy between the degree of nasal symptom disturbance and the level of discomfort perceived by individuals. Therefore, it is essential to consider personalized treatment plans tailored to each case.
When considering treatment strategies, nasal allergy has certain characteristics compared to other atopic conditions such as bronchial asthma and atopic dermatitis. These features of nasal allergies (e.g., hay fever and cedar pollinosis):

Relatively simple pathophysiology: The primary mechanism is derived from Type 1 allergic reaction, making it highly responsive to pharmacotherapy (e.g., second-generation antihistamines, anti-leukotriene receptor antagonists, and intranasal corticosteroids).
Easily identifiable causes (triggering responsible antigens): This facilitates effective treatments such as sublingual immunotherapy (desensitization therapy).
Localized allergic reaction: The site of the allergic reaction is well-defined, allowing for surgical options (e.g., CO2 laser cauterization of the inferior nasal turbinates).

At the Department of Otolaryngology, Â鶹AV Hospital, we operate specialized outpatient clinics for nasal and paranasal sinus allergies on Tuesday and Thursday afternoons. Here, our ENT specialists and allergy experts collaborate to provide professional care. Treatment options as those mentioned above, are carefully selected and presented based on the patient's symptoms and specific preferences.