花粉过敏 in English is Hay Fever, here is brief instruction I found:

Hay fever (allergic rhinitis) is one of the most common chronic conditions in the United States, affecting an estimated 35 million people. The condition may cause you to sniffle, drip and itch your way through the blooming months or while exposed to other allergic triggers.

If you have hay fever, relief may be on the way. There are many ways to treat hay fever. Medical advances during the past few years have brought new and improved drugs, both over-the-counter (OTC) and pre????ion.

Signs and symptoms of hay fever may include:
Congestion
• Runny nose
• Frequent sneezing
• Watery eyes
• Itchy eyes, nose, roof of mouth or throat
• Cough
If you're lucky, your reactions are mild. If you're not so lucky, your symptoms can be severe enough to disturb your sleep and trigger asthma, recurrent sore throats, headaches, fatigue and irritability. If you also have asthma, you may wheeze or become short of breath.

There are a lot of medicines for Hay fever, I list two of them:

CLEMASTINE (KLEM-as-teen)
BECLOMETHASONE (be-kloe-METH-a-sone)

More information go to drug store's website, some medicines need doctors’ instructions.