Taking Allergy Research Further
For Communities, Medications, and the Planet
Anna Chen Arroyo, MD
May 20, 2025
By John Knox
Come springtime, it seems like nearly everyone is dealing with allergies — whether it’s sneezing and itchy eyes from pollen or more serious symptoms like difficulty breathing caused by allergic asthma. In fact, about one in four people is allergic to something. Yet despite how common allergies are, many aspects of them remain elusive.
“An allergy is a specific immune reaction to a harmless substance in our environment,” explains Anna Chen Arroyo, MD, clinical associate professor and section chief of allergy, asthma, and immunodeficiency in the Division of Pulmonary, Allergy, and Critical Care Medicine. “We still don’t fully understand why some people develop allergies, why some develop them later in life, or how we outgrow some types of allergies.”
While these questions remain, Arroyo and her colleagues in the Stanford Allergy, Asthma, and Immunodeficiency section are making important strides — especially in understanding how allergies impact different communities.
Shining a Light on Allergies in Different Communities
With support from the Stanford Center for Asian Health Research and Education (CARE), Arroyo is investigating allergic disease patterns in Asian American populations. She recently published several studies (see sidebar) examining allergy trends among Asian American children, and the findings are striking.
For example, certain populations of Asian American children are 40% more likely to develop a food allergy compared to Non-Hispanic White children.
“The Asian American population is often viewed as a single, uniform group in large datasets,” Arroyo notes. “But when we looked more closely, we found variances among different Asian American ethnic groups. Filipino children, for instance, are significantly more likely to experience conditions like eczema, asthma, and food allergies than Non-Hispanic White children.”
Her team, which includes a partnership with Sutter Health researchers and physicians, uses electronic health record data to identify these patterns and explore possible contributing factors — including early-life exposures, migration history, and diet.
Arroyo hopes to bring this research into clinical practice by establishing a dedicated allergy clinic in Oakland Chinatown, where Stanford currently operates a pulmonary clinic under the leadership of Arthur Sung, MD, clinical professor and senior associate chief in the Division of Pulmonary, Allergy & Critical Care Medicine. The goal will be to improve access to culturally competent allergy care for Asian American communities.
Chemotherapy Allergy Care
Beyond food and environmental allergens, the team, along with Anne Liu, MD, clinical associate professor of allergy, immunology and rheumatology in the Department of Pediatrics and an expert on drug desensitization, is also studying allergic reactions to medications. They are particularly interested in medications that are critical for treatment, such as chemotherapy drugs.
“As people age, they may develop new allergies to medications,” Arroyo says. “But there are specific ways to manage this so that patients can still receive the therapeutics they need.”
In cases where patients are allergic to necessary first-line treatment, like platinum-based chemotherapy agents, her team collaborates with oncologists. Together they provide drug desensitization, which is a series of carefully controlled protocols that expose patients to the medication gradually. Desensitization helps the immune system temporarily tolerate the drug safely.
Read More About Research from the Allergy, Asthma, and Immunodeficiency Section:
- An opinion piece about the information vacuum around allergies and asthma in Asian American children.
- An NBC News article on why young Asian Americans are 40% more likely to develop allergies.
- An article published in The Journal of Allergy Clinical Immunology: In Practice about considerations for care for Asian Americans with allergies.
- An NPR report about the environmental impact of asthma inhalers.
- A perspective piece published in JAMA about greenhouse gas emissions and costs of inhalers in the U.S.
- An article about risk of childhood asthma among Asian Americans, Native Hawaiians, and Pacific Islanders
- An article about ethnic variation in childhood asthma prevalence among Asian Americans and Pacific Islanders.
- An article about asthma heterogeneity among Asian American children.
“While inhalers are critical for helping people breathe, they also contribute to the health care sector’s carbon footprint”
The Environment and Allergy: A Two-Way Street
Allergy is deeply tied to our environment — and as the climate changes, the prevalence of allergies seems to be rising. But there’s a surprising twist: some treatments for respiratory diseases like asthma may also be contributing to environmental harm.
Metered-dose inhalers, which are widely prescribed for asthma and chronic obstructive pulmonary disease (COPD), use hydrofluorocarbon propellants. These propellants are potent greenhouse gases that can trap heat thousands of times more effectively than carbon dioxide.
“While inhalers are critical for helping people breathe, they also contribute to the health care sector’s carbon footprint,” says Arroyo.
Her colleague in the Allergy, Asthma, and Immunodeficiency section, Clinical Assistant Professor Jyothi Tirumalasetty, MD, led a recent study published in The Journal of the American Medical Association (JAMA) that examined the emissions and costs of inhalers prescribed to Medicare and Medicaid recipients.
The findings highlighted just how significant the inhalers’ environmental impact can be. For context, using one metered-dose inhaler emits roughly the same amount of greenhouse gases as driving 60 miles in a typical gas-powered car.
To reduce emissions without compromising patient care, the team is advocating for thoughtful prescribing practices that can balance clinical effectiveness, affordability, and environmental impact in shared decision making with patients.
Searching for Answers
Arroyo and her colleagues in the Stanford Allergy, Asthma, and Immunodeficiency section continue to probe into the mysteries behind allergies — why they develop, why they’re increasing, and how the immune system reacts to changing environmental factors.
While the questions are complex, the program’s mission is clear: to bring inclusive, evidence-based care to every community so that everyone can breathe a little easier.
About The Allergy, Asthma, and Immunodeficiency Program in the Division of Pulmonary, Allergy, and Critical Care Medicine Division
