[조명구 엠블병원 병원장] House dust mites, cockroaches, pets, and mold were found to be representative indoor causes of allergies.
There are 30,000 species of dust mites found on Earth. It is the insect that produces the most important allergens, and in Korea, the American house dust mite and the European house dust mite are the most common. It is a small insect measuring about 0.3 mm in size and lives by eating skin scraps or food scraps from animals, including humans. Females lay 25 to 50 eggs every three weeks, and their lifespan is about two years.
The best habitat is bedding such as bed mattresses and static blankets, and they also inhabit sofas, carpets, and clothing. The appropriate temperature for habitat is over 25 degrees, and the comparative humidity is over 60%. The population increases seasonally in the summer, but rapidly decreases from the fall, with the lowest number observed in the winter.
As modern residential environments have changed to environments where heating and humidification are well maintained all year round, there have been many changes in the year-round ecology of ticks, narrowing the difference in reproductive capacity between winter and summer.
In particular, exposure to tick allergens at a young age increases the incidence of asthma and atopic dermatitis, and the sensitization rate to house dust mites in Korea is known to be about 90% of pediatric asthma patients, 50-70% of adult asthma patients, 70% of allergic rhinitis patients, and 60% of atopic dermatitis patients.
Animal dander, skin tags and cockroaches are the most problematic for cats and dogs, but cats are more likely to cause allergies than dogs. The source of allergens for cats, dogs, horses, and cows is hair, dander, and saliva, and for rats, it is urine, and the size is less than 7μm.
Allergens are not filtered out by a typical vacuum cleaner’s filter and can float in the air for a long time. Simply sitting or walking and using a heater or air purifier can also cause a lot of allergens to float in the air.
Cat allergens have strong adhesion, so they can easily stick to walls, carpets, and furniture. They also stick to clothing, so they can be carried to schools or workplaces, or even inside the house. For this reason, cat allergens are found even in homes without cats. Even if you get rid of your cat, a significant amount of it will remain in your carpet, bed, or furniture for several months. Cockroaches can also be a major allergen in Korea.
Sunyong Lee (sylee@edaily.co.kr)
