Lu Morales, 32, grew up eating a wide variety of Mexican
seafood dishes. But at age 25, a takeout meal of shrimp egg rolls suddenly led
to anaphylactic shock, an ambulance ride to the hospital and the diagnosis of a
shellfish allergy.
اضافة اعلان
Morales, said the egg rolls caused coughing, wheezing and
red, puffy eyelids. Now, Morales said, shellfish is completely off limits.
While most people will not experience the gain — or loss —
of allergies in adulthood, it is also not unusual, said Dr Shradha Agarwal, an
allergist and immunologist at the Icahn School of Medicine at Mount Sinai in
New York City. Why allergies wax or wane, especially in adulthood, is largely
not understood by scientists.
“There’s a lot of mystery in allergy,”Agarwal said.
What experts knowAllergies come in many forms and generally develop when your
immune system mistakenly treats a harmless allergen, like pollen or animal
dander, as a threat, Agarwal said. It then reacts every time it encounters that
allergen, with symptoms that can vary from coughing, sneezing and itchiness to
more serious reactions including hives, vomiting, trouble breathing and loss of
consciousness.
About 26 percent of adults and 19 percent of children in the
US have a seasonal allergy, and about 6 percent of adults and children have a
food allergy, according to the Centers for Disease Control and Prevention.
The causes of allergies are complex, said Dr Corinne Keet, a
professor of pediatric allergy immunology at the University of North Carolina
School of Medicine — depending on your genes and what kinds of allergens you
are exposed to and when.
But experts think that, in general, things that disrupt your
immune system — such as puberty, pregnancy, transient or chronic illnesses, or
organ transplants — “can change your allergic responses to things that you
previously tolerated,” Keet said.
Experts do not know how common it is for allergies to
develop in adulthood, said Ruchi Gupta, a professor of pediatrics who
specializes in allergy at the Northwestern University Feinberg School of
Medicine, although we do have some data related to food allergies. In a survey
of more than 40,000 adults in the US published in 2018, Gupta and her
colleagues found that about 45 percent of those who had food allergies
developed at least one new food allergy in adulthood. Of this group, a quarter
never experienced food allergies as children.
An important question for researchers, Gupta said, is what
exactly might cause adults to develop an allergy to a food they’ve eaten
before. Right now, she said, we do not know.
Dr Jyothi Tirumalasetty, a practicing allergist and clinical
assistant professor of medicine at Stanford University, has seen patients of
all ages develop various kinds of new allergies, including some to common
allergens such as pollen, pet dander, or tree nuts.
What about allergies that disappear?“Losing” an allergy, or becoming “desensitized” to an
allergen, happens frequently, Tirumalasetty said, especially beginning around
(or after) middle age. Our immune responses “quiet down,” becoming weaker and
less vigorous as we age, she said.
Some allergies are more likely to “resolve” than others,
Keet said. Most penicillin allergies disappear over time, and seasonal
allergies tend to lessen as you age, she said.
And while it is much less common to grow out of certain food
allergies such as those to tree nuts, fish and shellfish, Gupta said, an
estimated 50 percent to 80 percent of children with milk or egg allergies grow
out of them by age 10.
One common way people discover environmental allergies is by
moving to a new area and encountering pollen they have never been exposed to,
Agarwal said. This wouldn’t technically be a “new” allergy, she said, but it’s
a distinction that can make research in this area challenging. Similarly,
moving away from such areas can lead to relief.
Molly Thessin, 30, who grew up near Nashville, Tennessee,
said she had year-round pollen allergies as a child and had to take
antihistamines regularly to relieve her symptoms. That all changed when she
moved to Dallas at 23.
“I stopped taking allergy medicine for the first time in my
life, and I was completely fine,” Thessin said.
A few years later, she moved to New York City, where she
currently lives, and the allergies returned. It turns out she is allergic to
most of the trees and plants in the Northeast, as well as to cats, dogs, mold,
and cockroaches.
What about prevention?As for whether there is anything adults can do to avoid
developing new allergies, Agarwal said, experts do not have the answer.
The only allergy prevention research right now is focused on
preventing food allergies in children, Gupta said, which has little to do with
preventing new allergies in adults.
At the end of the day, Keet said, you can’t really control
whether you develop a new allergy as an adult. So, she said, “I wouldn’t worry
about it.”
Read more Health
Jordan News
.jpg)
.jpg)
