The freaky part of allergy season that no one warned you about

Pollen allergy season is getting longer and more intense as the climate changes, creating more misery for allergy sufferers. But it’s not the only type of allergy threat getting worse with warming.

There are other allergens, like mold spores, whose spread coincides with higher temperatures and weather disruption. But one of the most insidious and underrated dangers is now coming from stinging and biting insects. These wasps, hornets, yellow jackets, and bees are showing up in new areas and in greater numbers as more places become suitable for their hives, nests, and colonies.

Insect allergies are much less common than pollen sensitivity across the population, but they can cause severe, deadly complications, and they are far less studied. According to the Centers for Disease Control and Prevention, on average, 72 people in the United States died from insect allergies per year over the past decade. But insect allergies send thousands of people to the emergency room every year, and millions of people live with the fear that the next insect that lands on them could ruin their day. “From a public health point of view, it’s been heavily underserved,” said David Golden, an allergy researcher and part-time faculty at Johns Hopkins University.

The result is that many people are experiencing allergic reactions from insects for the first time, sometimes unsure of where they’re coming from. Many doctors are also unaware of how to diagnose and treat insect allergies. And as the climate changes, the allergy threat from arthropods is likely to get worse.

Changes in the climate are making the world more welcoming for insects that bite and sting.

Warmer winters and earlier springs mean more critters like yellow jackets and hornets survive the cooler seasons and emerge early in the year in greater numbers. And as temperatures continue to rise, previously inhospitable parts of the country are becoming habitable for insects, allowing species like fire ants to migrate further north.

That’s bad news for the 3 percent of adults and 1 percent of children who have insect allergies. Stinging insect venom in particular is notorious for causing anaphylaxis, a life-threatening allergic reaction where blood pressure plummets and airways swell, making it difficult to breathe. And most people don’t know that they’re allergic until they’ve been bitten or stung.

Golden explained that there are three broad categories of insects that concern allergy specialists: bees, wasps, and ants. People who have insect allergies are not necessarily allergic to all of them, and even within these groups, someone can react to one variety but not another. There are treatments such as immunotherapy that can protect an allergy sufferer from insect sting complications, but they often provide relief from the bite of just a specific kind of insect.

That was evident in Europe in recent years with the arrival of the invasive Asian hornet. “They were reporting that even people who were known to be allergic to yellow jackets and hornets were getting the allergy shots — venom immunotherapy — to protect them and they were stung by yellow jackets and hornets and they were fine,” Golden said. “But when they got stung by this Asian hornet, they had anaphylaxis all over again. It’s another allergy.”

In the US, fire ants are also a major concern for allergy sufferers. This is an aggressive, hardy invasive species that took root in the warm climate of the southern and southeastern US, but is gradually moving northward. Their range now reaches Virginia, and they sporadically pop up in Maryland.

Strictly speaking, ticks are not insects, but they are also moving further north as the climate warms. The spread of the lone star tick is particularly concerning because it can trigger a dangerous allergy condition known as alpha-gal syndrome. When the tick bites a host, it transmits a sugar that makes victims react to red meat like beef, pork, and lamb, as well as products made from mammals. Climate change is also helping spread the ticks that carry Lyme disease.

All of these factors are converging in America’s largest state, which is warming up to three times faster than the global average. And since the climate there is starting from such a cold baseline, many residents are encountering allergy triggers for the first time the hard way.

“We did a study that showed the further north you went, the higher the prevalence of people seeking health care, urgent care for stinging events,” said Jeffrey Demain, an allergist in Anchorage, Alaska, and clinical professor at the University of Washington. “With milder winters, you have more survival of the hibernaculum, so the queens, they come out in the spring, and they’re already impregnated.”

Alaska is also getting walloped hard by pollen and mold. “Birch pollen levels can become incredibly high here,” Demain said. “In fact, we oftentimes are the highest in the world. We kind of trade off between Finland, Sweden, and Alaska as far as who has the highest levels.” Sensitivity to pollen can also trigger reactions to certain fruits, vegetables, and nuts, a phenomenon known as pollen food allergy syndrome or oral allergy syndrome. And as warmer air moves in, there’s a growing shift from snow to rain, as well as an increase in intense rain events. More rain means more humidity, which means more mold, which in turn causes major problems for buildings in Alaska built to insulate against the cold.

There are other environmental threats mixed into all this as well. Alaska has seen an increase in large wildfires in recent years and is projected to burn more as average temperatures rise. These fires send huge clouds of smoke and ash into Alaska’s cities, towns, and villages. “Even though that might not be in your immediate area, it causes a tremendous amount of pollution, and the particulates in the air can travel long, long distances,” Demain said. The degraded air quality can irritate airways and make people more susceptible to allergens.

It shows that allergies don’t exist in a vacuum and that climate change can create health problems that intersect and exacerbate each other.

Looking at allergies alone doesn’t tell the whole story about the magnitude of the threat. It also shows that it’s essential to slow the underlying changes to the climate by reducing fossil fuel consumption and greenhouse gas emissions in order to tamp down on the dangers of future allergies and related complications.