アレルギー性鼻炎の最新治療・舌下免疫療法

Allergic rhinitis is a typical type I allergy in which allergic conjunctivitis and allergic rhinitis develop. Approximately ２５％ of the Japanese population are affected by Japanese cedar pollinosis and proportion of severe status patients is higher than with grass or ragweed pollinosis, which are the representative condiotions in other countries. Many of the patients with cedar polinosis have also been sensitized to cypress pollen which disperses after cedar pollen. Consequently, symptoms of cedar pollinosis are followed by those of cypress pollinosis, so the symptoms last, though they are seasonal, for as long as four months from February to May.
Pharmacological therapy prescribed by general practitioners is the common modality for the treatment of allergic rhinitis. However, both oral and topical medications are symptomatic treatment. They do not cure it or remain effective until the following year.
Sublingual immunotherapy（SLIT）is safer than subcutaneous immunotherapy（SCIT）that is conventional antigen-specific immunotherapy, the only treatment modality by which complete cure of the disease can be expected. Treatment with SCIT requires special attention because it may cause, as a side effect, anaphylactic shock, which prevents the therapy from becoming popular in Japan. In order to reduce the possibility of this side effect, immunotherapy is administered by other routes, such as sublingual, intranasal, oral and transbronchial in Europe and the United States. SLIT has become popular and the efficacy of SLIT has been proven in placebo-controlled, double-blind comparative studies using pollen and house dust mite. As for side effects due to SLIT, there are no reports of anaphylactic shock, but oral itching and swelling, skin reaction, and mild asthma-like attacks have been reported. Oral itching is usually diminished for a few times after allergen administration.