Without rain to tamp it down, pollen has gone airborne, signaling that spring allergy season has arrived in Marin.

“The grass pollen already started up a couple of weeks ago, and the juniper pollen a couple months,” said Dr. Schuman Tam, an allergist at MarinHealth Medical Center in Greenbrae. “The allergy season is starting earlier and lasting longer.”

Hay fever, or allergic rhinitis, brings itchy eyes, runny noses, sneezing, smelling difficulties, sore throats and skin irritation. A quarter of adults and 20% of children in the U.S. suffer from seasonal allergies, according to estimates from the Centers for Disease Control and Prevention.

Data from the USA National Phenology Network show that on average, the start of spring has occurred earlier since 1984. A study published in the Proceedings of the National Academy of Sciences of the United States of America found that nationwide, pollen amounts have increased by up to 21% between 1990 and 2018.

However, the organization says spring blooms — and the pollen that comes with them — in Northern California and Oregon are more related to precipitation. Two years ago marked the beginning of the El Niño weather cycle — bringing a wetter, warmer winter to the area.

Tam said this spring will likely be similar to the past couple of years because of it.

“We expect a very high pollen count,” Tam said.

There is no pollen counter specific to Marin, although the numbers are similar to pollen counters in San Jose and Pleasanton operated by the American Academy of Allergy, Asthma and Immunology.

San Jose’s reading on Monday showed high levels of tree pollens — oaks, juniper, cedar and sycamore — and low concentrations of pollens from grasses.

Pleasanton’s reading on Monday showed high levels of oak, sycamore and pine tree pollens.

Allergists say they don’t need an exact reading of the pollen count in Marin to know that the pollen count is high. They have the evidence in the surge of patients with heavier and more diverse symptoms than in the past.

Tam agreed that oak and juniper are common culprits in the North Bay, as are grass pollens.

Tam said he expects the spring bloom to deliver a pollen storm in May, when all the grasses, juniper and oak are broadcasting the allergens.

Global warming is also playing a part in the length of spring allergies, said Dr. Lindsay Finkas, the chief of allergy and immunology at Kaiser Permanente.

“What we are seeing is that there are prolonged pollen seasons as a result of warming temperature,” Finkas said. “This can result in longer allergy season and increased symptoms for those who suffer from seasonal allergies.”

Experts suggest using over-the-counter, nonsedating antihistamine such as loratadine, fexofenadine, cetirizine or levocetirizine to treat symptoms. Eye drops and nasal steroids can also do the trick.

Allergists do not recommend medications like diphenhydramine, found in drugs such as Benadryl, because it can affect concentration and the ability to operate machinery.

“And if you’re still suffering, seeking out the advice of your physician and seeking evaluation with an allergy specialist where we can help alleviate these symptoms is something I’d recommend,” Finkas said.

Allergy shots and other methods of continued treatment could be an option for those folks. These treatments can involve monthly injections over five years and are about 80% effective.

If the allergies are out of control, it could be a sign of a sinus infection, Tam said.

If allergies are causing coughing or wheezing, that could be associated with asthma. People with those symptoms should see a doctor, as it could be life-threatening, Tam said.

One remedy is avoidance, Tam said. People who enjoy outdoor activity can try exercising indoors instead, he said. “Take medication; close windows; if it’s bad, do not exercise outdoors for a few months,” Tam said.

“Taking a shower or rinsing your nose with a saline rinse or spray can clear out those pollen exposures,” Finkas added.