Jeffrey Bryant is used to the discomforts of hay fever in spring, when trees normally bloom in his hometown of Louisville, Ky. this year was different: Bryant felt his symptoms come on with a vengeance when it was still January, the Wall Street Journal reported.

“It’s never been as bad as this and never started as early,” Bryant said. the 48-year-old computer programmer usually relies on medications to ease his coughing, sneezing and other symptoms. Now, he is working with his doctor to get started on a series of shots that he hopes will control his allergies within a few weeks.

Mild winter temperatures in many parts of the country—the fourth warmest winter since record-keeping began—have triggered an unusually early release of pollen from trees. that bodes badly for the millions of people who suffer from allergic rhinitis—commonly known as hay fever.

Allergists are predicting a longer, and more intense, allergy season than normal. once people have been exposed to the early pollen, essentially priming the immune system to react to the allergens, there is little chance of relief even if temperatures cool down again. this priming effect can bring on even more severe symptoms for allergy patients, especially those with asthma, says Neil Kao, an allergist in Greenville, S.C.

Medications, including eye drops, antihistamines and nasal sprays, can relieve hay-fever symptoms for many people. For greatest effect, these products usually need to be used just before any exposure to pollen, says Stanley Fineman, an allergy specialist in Marietta, Ga. But this year “we didn’t catch it in time because we didn’t know the pollen was going to start so early,” said Fineman, who also is president of the American College of Allergy, Asthma & Immunology, which represents allergists. Weather websites often signal when local pollen counts start to rise.

More aggressive treatments, including immune-boosting allergy shots, are also available, and specialists expect more patients may pursue these remedies this year if their symptoms are worse than normal.

Different pollens serve as triggers to different people. Allergy shots, which administer escalating doses of the offending allergens, work like a vaccine to create resistance in the patient. But these can take several months to become effective. Doctors increasingly are recommending faster treatment protocols that deliver the shots over a shorter period and can bring relief within a few weeks.

Allergists also may offer the same type of immunotherapy in the form of drops under the tongue, which patients can use at home after an initial visit. Pharmaceutical firms are developing immunotherapy tablets, to be taken orally, including one from Merck & co. that has been shown in trials to reduce symptoms of ragweed allergy.

Other researchers are investigating new methods to give patients faster and more effective allergy relief, such as delivering the allergens through the skin or by way of the lymph nodes.

As many as 30 percent of children and up to 40 percent of adults suffer from seasonal allergies that cause reactions such as sneezing, itching, stuffy nose, and watery eyes. Trees are one of the earliest plants to release pollen, followed later by pollen from grass and flowering plants. For example, high concentrations of tree pollen in Kansas City, Mo., Tuesday came mainly from juniper, elm and maple trees, according to data compiled by the National Allergy Bureau, part of research group American Academy of Allergy, Asthma & Immunology. Ditto for Atlanta, where the top offenders were pine, oak and birch.

Some studies suggest climate change, by promoting longer blooming seasons, may increase the prevalence of certain allergens and the time during which people are exposed to them. Warmer temperatures also can boost concentrations of mold, another allergen that is usually killed by colder weather, said James Sublett, the Louisville allergy specialist treating Mr. Bryant.

Improved medications have been introduced to treat allergy symptoms in recent years, including antihistamines, nasal steroid sprays and drugs that block inflammatory chemicals produced by the body. the products are generally safe and effective. But in a large survey of adults presented at an annual allergy conference in 2006, about a third of respondents said they switched medication either because of a lack of effectiveness or side effects.

Unlike medication, allergy shots can potentially lead to lasting remission of symptoms after three to five years.

The treatment, which is formally known as subcutaneous immunotherapy and is generally covered by health insurance plans, may also help prevent development of asthma and new allergies. the shots are typically given once or twice a week for about five months, after which their frequency is reduced.

Growing in popularity is a faster treatment, known as “cluster” therapy, that involves two to four injections one day a week for three weeks. Patients’ own immune systems are mobilized and able to counteract naturally occurring allergens often within a few weeks, says Richard Weber, an allergy specialist at National Jewish Health in Denver. Risks include an increased chance of irritation at the injection site and a possibly serious reaction to the allergen.

Rachel Lowe, a 40-year-old plastic-surgery nurse in Marietta, Ga., recently started cluster shots recommended by Fineman after her allergies kicked in in early February. “I always dread when everything is in bloom because my allergies are so bad that I need to lock myself indoors sometimes and can’t enjoy the spring,” she said.

Some physicians are administering drops under the tongue, known as sublingual immunotherapy, that contain the same substances used in shots. the technique has been used since the 1980s in Europe, where it has been shown to produce lasting remissions in long-term use. It doesn’t have U.S. regulatory approval, but some doctors give it to patients anyway as an “off-label” use of the substance.

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