FUKUOKA – Hay fever, with its attendant sneezing, runny nose and other allergy symptoms, is most commonly attributed to pollen and mites.
But it can also be triggered by contact with moths, cockroaches and other insects, according to a new medical study.
The study, based on information supplied by 20 medical institutions across Japan, is the first nationwide survey of its kind.
The results of the survey were presented Thursday at the opening of a meeting in Fukuoka of the Oto-Rhino-Laryngological Society of Japan.
While it has been known that asthma can be caused by contact with the gnatlike flies known as midges and with other insects, the study provides new evidence that insects can also trigger allergies leading to nasal inflammation.
The study was based on testing done last summer on 560 patients at the 20 facilities. The goal was to see if they had antibodies that would fight allergic reactions to 13 antigens, including cockroach feces and moth particles.
The tests showed that 66 percent of the patients had the antibodies for antigens associated with house dust, while 57 percent had those associated with cedar pollen, 33 percent those for moths, 16 percent those for midges and 13 percent those for cockroaches.
When wax paper soaked with insect extracts was placed inside the patient’s nostrils to induce sneezing and runny nose symptoms, 62 percent of the patients with high levels of antibodies reacted to moth extracts and 44 percent to cockroach extracts.
In autumn, when the moth and midge populations grow, the number of patients carrying those antibodies also rises, the study showed. This reveals that there is a seasonal nature to humans’ allergic reactions to insects — just as there is with pollen.
“We cannot underestimate the influence of cockroaches in the summer, and moths and midges in the autumn,” said Minoru Okuda, a professor emeritus at Nippon Medical School who led the research team. “While one may assume it’s the pollen, there’s a possibility that the cause (of allergies) is insects.”
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