This year, spring has started early. The trees are budding, and the flowers are blooming. What's not to love?

Allergies, of course! Especially tree-pollen allergies. About 40% of Americans suffer from seasonal allergies. Millions of people are experiencing the sneezing, watery eyes, runny nose and congestion that allergies bring. But this year, the symptoms have started earlier than usual. "People were caught by surprise," says Dr. Alvin Sanico of the Johns Hopkins Hospital.

Allergy treatment often works best when it is taken before the arrival of pollen, which tends to peak in April. This year, sufferers didn't have time to get help early.

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