The number of hay fever patients in the country jumps in spring due to ramped-up levels of dust, as the country is buffeted by sandstorms and cloaked with haze laced with fine particles.
A five-year study recently released by the Health Insurance Review and Assessment Service showed that hay fever cases most commonly develop and occur in March and April.
The total number of patients rose by an average of 3.4 percent each year, from 5.49 million in 2009 to 6.27 million in 2013.
Hay fever, also known as allergic rhinitis, is an immunological disease triggered by hypersensitivity to alien substances like sand dust and pollen in the nasal mucous membrane.
"Antihistamines and steroids can be effective in treating the symptoms, but the best preventative measure is to avoid allergens. It's advisable to get rid of dust mites and refrain from going outside during the high season of sand dust and pollen," said Lee Jeung-gweon, a rhinology professor at Yonsei University's Severance Hospital in Seoul.