Climate change may worsen allergy symptoms, but does not necessarily increase the number of people with allergies, a new study has found.
File Photo by KatePhotographer/Shutterstock
Nov. 5 (UPI) -- Children with asthma in Los Angeles have not seen an increase in allergy diagnoses, despite effects from climate change on the air they breathe, a study presented Friday during the American College of Allergy, Asthma and Immunology annual meeting found.
The percentage of children in the Los Angeles area with allergies to dust mites, cat, dog, cockroach, tree pollen, grass pollen and weed pollen remained relatively unchanged between 1999 to 2014, the data showed.
For example, the percentage of children with allergies to at least one grass, tree, weed or dog allergen held steady at 0.25% or less over the 15-year period.
Similarly, the percentage of children with allergies to dust mites or cockroaches was 0.35% or less over the entire period.
This is despite documented increases in the length of growing seasons and pollen counts due to climate change, they said.
"Although temperatures have been rising and pollen loads increasing, if someone is not genetically predisposed to allergies, they are not likely to be sensitized to more allergens," study co-author Dr. Lyne Scott said in a press release.
"The growing season is year-round in L.A. and people with allergies who are already sensitized to pollens suffer more intensely when the growing season is longer, or the air quality isn't good," said Scott, an allergist who practices in Los Angeles.
However, those with allergies may have worse symptoms because of the effects of climate change, she added.
A study published earlier this year suggested that allergy symptoms may worsen for sufferers due to the warming climate.
Still, despite dire predictions, there is little evidence that climate change will necessarily increase the number of people with allergies.
For this study, the researchers tested nearly 6,000 children in Los Angeles who had been diagnosed with asthma and allergic rhinitis, or hay fever, for allergies to dust mites, cat, dog, cockroach, tree pollen, grass pollen and weed pollen, using standard skin prick tests.
In these tests, allergists prick the skin of a test subject with a pin containing a sample of an allergen and monitor the reaction.
If the skin reacts, such as with a rash, that indicates the test subject is likely allergic to the substance.
After performing more than 123,000 tests on study participants, the researchers found no increase in the number who experienced "allergic sensitizations" over the 15-year study period.
When a person's immune system becomes sensitized to an allergen, or an otherwise harmless substance such as dust or dog hair, they will likely develop symptoms of an allergy each time they are exposed to that same allergen, the researchers said.
High pollen counts, for example, do not mean that individual allergy sufferers will be affected, they said.
This is because there are many types of pollen, from various kinds of trees, from grass and from a variety of weeds. As a result, a high overall pollen count does not always indicate a strong concentration of the specific pollen to which individuals are allergic.
"We were somewhat surprised at the results as we expected there would be an increase in the number of kids with asthma who were sensitized to pollen and other allergens," study co-author Dr. Kenny Kwong said in a press release.
"Between 80% to 90% of children with asthma have allergy triggers, which is why it's important for children with asthma to be tested for allergies," said Kwong, an allergist who also practices in Los Angeles.
Nov. 5 (UPI) -- Children with asthma in Los Angeles have not seen an increase in allergy diagnoses, despite effects from climate change on the air they breathe, a study presented Friday during the American College of Allergy, Asthma and Immunology annual meeting found.
The percentage of children in the Los Angeles area with allergies to dust mites, cat, dog, cockroach, tree pollen, grass pollen and weed pollen remained relatively unchanged between 1999 to 2014, the data showed.
For example, the percentage of children with allergies to at least one grass, tree, weed or dog allergen held steady at 0.25% or less over the 15-year period.
Similarly, the percentage of children with allergies to dust mites or cockroaches was 0.35% or less over the entire period.
This is despite documented increases in the length of growing seasons and pollen counts due to climate change, they said.
"Although temperatures have been rising and pollen loads increasing, if someone is not genetically predisposed to allergies, they are not likely to be sensitized to more allergens," study co-author Dr. Lyne Scott said in a press release.
"The growing season is year-round in L.A. and people with allergies who are already sensitized to pollens suffer more intensely when the growing season is longer, or the air quality isn't good," said Scott, an allergist who practices in Los Angeles.
However, those with allergies may have worse symptoms because of the effects of climate change, she added.
A study published earlier this year suggested that allergy symptoms may worsen for sufferers due to the warming climate.
Still, despite dire predictions, there is little evidence that climate change will necessarily increase the number of people with allergies.
For this study, the researchers tested nearly 6,000 children in Los Angeles who had been diagnosed with asthma and allergic rhinitis, or hay fever, for allergies to dust mites, cat, dog, cockroach, tree pollen, grass pollen and weed pollen, using standard skin prick tests.
In these tests, allergists prick the skin of a test subject with a pin containing a sample of an allergen and monitor the reaction.
If the skin reacts, such as with a rash, that indicates the test subject is likely allergic to the substance.
After performing more than 123,000 tests on study participants, the researchers found no increase in the number who experienced "allergic sensitizations" over the 15-year study period.
When a person's immune system becomes sensitized to an allergen, or an otherwise harmless substance such as dust or dog hair, they will likely develop symptoms of an allergy each time they are exposed to that same allergen, the researchers said.
High pollen counts, for example, do not mean that individual allergy sufferers will be affected, they said.
This is because there are many types of pollen, from various kinds of trees, from grass and from a variety of weeds. As a result, a high overall pollen count does not always indicate a strong concentration of the specific pollen to which individuals are allergic.
"We were somewhat surprised at the results as we expected there would be an increase in the number of kids with asthma who were sensitized to pollen and other allergens," study co-author Dr. Kenny Kwong said in a press release.
"Between 80% to 90% of children with asthma have allergy triggers, which is why it's important for children with asthma to be tested for allergies," said Kwong, an allergist who also practices in Los Angeles.
No comments:
Post a Comment