Around 20% to 25% of Americans are plagued by seasonal allergies. You're especially vulnerable if you live in one of the top five most challenging seasonal allergy cities:

• Wichita, Kan.

• Virginia Beach, Va.

• Greenville, S.C.

• Dallas

• Oklahoma City

Those cities top the list of places with higher-than-average pollen counts, high sales of over-the-counter allergy medicines, and fewer allergists.

But wherever you are, you want to take steps to tamp down your allergic reaction:

• The American College of Allergy, Asthma, and Immunology suggests spring cleaning to remove the allergy-worsening dust, mold, and pet hair and dander that's accumulated over the winter. But don't open the windows to bring in "fresh" air — that's an invitation to pollen.

• If your central heat and air conditioning has filters, change them every three months. Use filters with a MERV rating of 11 or 12. Otherwise, you can consider several standalone HEPA air filters.

• Don't keep flowers you’re allergic to in the yard. The worst culprits include asters, chrysanthemums, daisies, sunflowers, lavender, baby's breath, and wisteria.

• Supplements that may ease your allergy symptoms include the flavonoid quercetin, which works as an antihistamine, and probiotics that ease inflammation and promote immune system health.

Medications you can get over the counter include second-generation antihistamines such as fexofenadine and loratadine. But don't take decongestants without your doctor's consent; they can raise blood pressure and cause a rapid or abnormal heartbeat.