What is better for chronic allergies an air purifier or a humidifier?

Purifier: The humidifier can actually make the issue worse.It is good to use one if the humidity is too low, below 30% can dry the nasal passages and lungs. Above 50% humidity will support the growth of house mites and above 70% you can expect mold growth. A good humidity gauge is important if you are going to use humidifiers for thease reasons. A good purifier removes offending agents from the air, period.